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Telit TRIZIUM Hardware User Guide

1. 1 2 3 4 3 6 7 8 9 10 11 1 X501 NX1255GB 6 000MHz a ee E ear oo Bas al M Bea UEO 3 092 100nF 0504 2188 PET 34 BEES XSR AHCIGUD4DCKRGA 11 10V 3 d 72 wa 0402 3 3V_HUB o R516 15K LTF R515 GND 4 0 5 7 FAM T4AHC1GU04DCKRG4 4 El 2 Uso4 4 xrin_Fr2232 i s ON ony 3D 9C 2 506 o 4 LP2982AIMS5X 3 3 50
2. 1 2 3 6 7 8 9 10 11 43 7V a ap 302 JP302 LP2982AIMSX 3 0 NOPB O E 1 5 e V_IN e 2 owp 26 202 3_lon orr Bypass 4 3 m 1 Uses 28 9 x O 63V 120A ci gt V 0603 MAOSA C305 25 C306 18304 2 XIR 10uF 25V lov 1 N NE nb CONT A 25 v 3 fen 0304 GND LDO ON OFF 5 1 11B 6C 4 6E 5 2B 5 2D 5 8C MAX3237CAI GN 2 55 28 5 O 23 6 e gt T2IN T20UT x 22 7 e 4 T3OUT o 19 10 a 4 T4OUT OS ao D2 SH 4 TIN TSOUT E 3 RIOUTB 2 77 216 riour RIIN 2 a GND 20 9 25 lt lt lt R20UT R2IN gt 5 x EQ rour H SEL xv 13 15 14 Oo MBAUD SHDN D 9 amp 2 amp 5 2 230v e 5 77 JP303 Po U301 E GND LP2982AIMSX 3 0 NOPB e m SO301 P EE CD81VISSAAC evn e e p PL301 PL302 PL303 2 1215061 10 1215061 10F 1215061 10F 2 26 2L C301 3 4 E n gt IX TRACE USB 4 1 e a 1 le 1 1 ON OFF BYPASS 5 ma 2 3L jaa E E US _
3. 50106 BAR CODE 0104 50105 ae MODIFY DATE PATH Archivio_PCB cs1170 DESCRIPTION FILENAME _ 1170 j CS1 1 70 FILE GERBER Dai T 2 oup I2CBUS DUAL CAMERA 1 Mod 048 Rev 0 6 99 ANNOTATION FORM Project by Silkscreen side A A3 Drawn by Pasqualini Natascia 06 09 2005 Project SHEETN OF SHEETS DRAWING CODE Vert by 0276 1 2 CS1170 SM 50101 NO NO TUTTI I DIRITTI RISERVATI RIPRODUZIONE E DIVULGAZIONE VIETATE ALL RIGHTS RESERVED REPRODUCTION AND DISCLOSURE FORBIDDEN 2 x MODIFY DATE PATH Archivio PCB cs1170 pm DESCRIPTION FILENAME _ 1170 j CS1 1 70 FILE GERBER Dai T 2 oup I2CBUS DUAL CAMERA 1 Mod 048 Rev 0 6 99 ANNOTATION FORM Project by Silkscreen side B A3 Drawn by Pasqualini Natascia 06 09 2005 Project SHEETN OF SHEETS DRAWING CODE Verif by 0276 2 2 CS1 1 70 SM
4. SOT 323 l 1 C2 ifs i 1 i 4v C NT Z BE i 77 Ex i Electret microphone GND 0402 mict 7 i C C3 1 T T 1 A er snielded To Mic Buffer amplifier d Cable i MIC 2 i i i 2 i 220nF i 1 7A t ov 084 27 0585 5554 2 544 GND GNO i i i ts in i i Gi t NOTE In the unbalanced application the capacitor C3 shall be gt 200nF otherwise the frequency response will be cut at low band frequencies down to 300Hz This capacitor can be placed close to the MIC pad EXT_MIC or INT_MIC depending on the audio path chosen or if possible it should be placed close to the shielded cable connector If the ground return path is well designed then it is possible to eliminate the C3 capacitor provided the buffer is close to the mic input O NOTE The cable to the microphone should be shielded O NOTE The microphone sensitivity changes with the value of R2 Usually the microphones are characterized with 2kQ biasing resistance so try to keep the value of R2 around 2kQ For mic characteristics refer to the manufacturer Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 30 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 6 4 Micr
5. 1 cage 804 89 1 300nr onour 5 m ES BNO 1 961 1 mri 1 i to C9140 rapa i ls BNO sour 400nF n MUTE CONTROLLED rn Ale ALWAYS DN 1 CONT E DES 1 7 1 AMPLI POWER CONTROL 1 1 1 1 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 42 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 8 General Purpose I O The general purpose I O pads can be configured to act in three different ways input output alternate function internally controlled Input pads can only be read and report the digital value high or low present on the pad at the read time output pads can only be written or queried and set the value of the pad output an alternate function pad is internally controlled by the GE864 firmware and acts depending on the function implemented Not all GPIO pads support all these three modes GPIO_06 ALARM supports all three modes and can be input output alarm output Alternate function GPIO 07 BUZZER supports all three modes and can be input output buzzer output Alternate function 8 1 Using a GPIO pad as INPUT The GPIO pads when used as inputs can be connected to a digital output of another device and report its status provided this device has interface levels co
6. 2 4 Y 15 5 238 2 2 gt aN R301 R302 R303 R305 8306 Uc aL sic TRACE RX TRACE 4 UM ax pex pex ex to 2 DOPROCUSB gt o 15 C304 5 5 5 5 5 Ala PE Lo o 5 2 5 5 Le ASCO eee le 4 los 0402 0402 0402 002 0402 5 HE c lt e PROG ous 5 le 5 dnb on CONT A E em 7L Lo 125 RING Dp 2 23 68 3 RS e d gt 2 Jez U303 GND 3r LO o 23C 7 E LDO_ON_OFF 5 7 9L e C108 DTR 1 498 9 1 11B 7B 4 6E 5 2B 5 2D 5 8C du MAX3237CAI Lo 2 3C n SSOP 28 e Z gt ile 2 e 25 nour O DCD 2 3 9 9 23 2 m d 15 O4 e gt aai O z RXD 23 3 e 9 corso a z e gt sin 07 gt to TXD O EL 2 3C 9 e 2 tam Tour DTR USB B RS232 e tsm Tsour 12 2 e GND c un 4 DSR A lt 7U lt lt run 5 4 RTS USB RS232 Switch lt 20 rour rain 1 4 to CTS 4 18 Rain lt lt 24 OB xb P 2 2 GND aN PE 59 zd o ae Zu Sz EO 5 a 58 2 ER MODIFY DATE PATH home users area DESCRIPTION FILE NAME cs1139a cir DAI TELECOM Dai Telecom Group Mod 067 rev 1 11 02 ANNOTAT
7. 1 pU n K iT ig i 1 iBy nM TO MIC 1 i 0603 iz s BEU Maks GM862 MIG Sz 5r assa 1 6S8 u m i ENG ENG 1 i 3V EXT MIC SINBLE 0701 D 225465 GM862_MIC 5 gt T34 EXT MIC SINGLE ou E ar 7 E gt 1 m 5 4 R717 R720 4 WIE 10k 7 2 De ax 9D BS 5 0603 S gE 0603 i ces i t C725 C720 715 10 55188 iQ nF 4 ret 1 dey aaa ST APER a 1 15V 5 0603 0603 0609 ENG ENG END The schematic does not include the required mic biasing circuitry For the biasing the same circuit as seen before can be used to be noticed that the capacitor C3 on the unbalanced biasing circuit is not anymore needed if this Buffered design is used Two different configurations are used one inverting and the other not inverting hence an additional 6dB 2 times gain is achieved by doubling the mic signal path The gain of the not inverting buffer is given by the formula R719 R720 and hence it cannot be less than 1 In the example shown the gain of the not inverting buffer is 1 5 4dB While the gain of the inverting buffer is given by the formula Gain 1 As shown in the balanced buffered mic the gain adjustments can be done by changing R719 R720 and R708 R711 and as a consequence the capacitors C726 and C727 Reproduction forbidden without writte
8. 7 Speaker 7 1 Speaker lines characteristics and requirements The Telit GE864 provides two audio paths for both the microphone and the earpiece the internal and the external audio paths Only one of the two paths can be active at a time and it is selectable by hardware line AXE or by AT command The audio characteristics of the two paths are slightly different and this should be kept in mind when designing your application The internal audio path should be used for handset function while the external audio path is suited for hands free function car kit Both speaker outputs from the Telit GE864 are bridged type and the OEM circuitry shall be designed bridged to reduce the common mode noise typically generated on the ground plane and to get the maximum power output from the device however for particular OEM application needs also a single ended circuitry can be designed The GE864 speaker output lines characteristics are internal speaker path EAR_MT EAR_MT e line coupling DC e line type bridged e speaker impedance operating conditions gt 16 5 1kHz minimum load impedance 150 e signal bandwidth 150 8000 Hz 3 dB maximum differential output 850 mV e rated output power 10 mW e maximum power output 30 mW e volume level steps SW 2dB e number of volume steps SW 10 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserv
9. All Right reserved Right of modification reserved page 2 of 60 Z Telit Communications S p A Telit GE 864 Hardware User guide 1vv0300694 Rev ISSUE 2 19 12 05 6 3 Microphone Biasing 6 3 1 Balanced Microphone biasing 6 3 2 Unbalanced Microphone biasing 6 4 Microphone buffering 6 4 1 Buffered Balanced Mic 6 4 2 Buffered Unbalanced Single Ended Mic 7 SPEAKER 7 1 Speaker lines characteristics and requirements 7 2 General Design rules 221 Noise Filtering 73 Handset earphone design 7 4 Hands Free earphone low power design 7 5 Kit speakerphone design 8 GENERAL PURPOSE I O 8 1 Using a GPIO pad as INPUT 82 Using a GPIO pad as OUTPUT 83 Using the Alarm Output GPIO_06 ALARM 8 4 Using the Buzzer Output GPIO 07 BUZZER 9 CAMERA 9 1 Camera characteristics 9 1 1 Camera interface connectors 9 1 2 EVB for Transchip camera support 9 1 3 Example usage script for camera 10 CONFORMITY ASSESSMENT ISSUES DOCUMENT CHANGE LOG ANNEX A EVK2 SCHEMATICS ANNEX B CAMERA EVB SCHEMATICS 28 29 30 31 31 33 36 36 38 39 39 41 41 43 43 43 44 44 45 45 45 47 48 49 50 51 57 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 3 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 1 Overview The aim of this
10. Telit GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 Telit Hardware User Guide Telit Communications S p A 2005 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 1 of 60 Telit GE 864 7 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 Contents 1 OVERVIEW 2 HARDWARE COMMANDS 2 1 Turning ON the GE864 2 2 Turning OFF the GE864 2 2 1 Hardware shutdown 2 3 Hardware Unconditional Reboot 3 SUPPLY 3 1 Power Supply Requirements 3 2 General Design Rules 3 2 1 Electrical design Guidelines 3 2 1 1 5V input Source Power Supply Design Guidelines 3 2 1 2 12V input Source Power Supply Design Guidelines 3 2 1 3 Battery Source Power Supply Design Guidelines 3 2 1 4 Battery Charge control Circuitry Design Guidelines 3 2 2 Thermal Design Guidelines 3 2 3 Power Supply PCB layout Guidelines 4 ANTENNA 4 1 Antenna Requirements 42 Antenna PCB line Guidelines 4 3 Antenna installation Guidelines 5 SERIAL PORT 5 1 RS232 level translation 5 2 5V UART level translation 6 MICROPHONE 6 1 Microphone line Characteristic and requirements 6 2 General Design Rules 9 9 10 10 11 12 12 14 14 16 16 17 18 19 21 23 25 25 28 Reproduction forbidden without written authorization of Telit Communications
11. The cable to the microphone should not be shielded instead a twisted pair cable shall be used NOTE The microphone sensitivity changes with the value of R2 R3 Usually the microphones are characterized with 2kQ biasing resistance so try to keep the sum of R2 and R3 around 2kQ Refer to your microphone manufacturer for the mic characteristics Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 29 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 6 3 2 Unbalanced Microphone biasing The unbalanced microphone biasing voltage should be obtained from a dedicated voltage regulator in order to eliminate the noise present on the power lines This regulator can be the same for all the audio paths The microphone should be supplied from a capacitor multiply circuit For example a circuit for the unbalanced microphone biasing can be 33 MIC MIC Biasing Regulator Capacity multiply circuit ge ee LeccceLezeLexsccu e eY ui LP2eSBO0A1MBX 3 0 hn vou i 25 C1 i R1 3 4 mur 40K i ON OFF i 4v 5 i l LORA pace MAQSB wo i 01 i 2 BCH47BW p
12. 16V e ge MIC_HE i Spi ta noMount YES a C414 5 5 GND GND luF e 0603 0603 GND GND 217 777 GND OPTIONAL POWER AMPLIFIER qt 50401 1401 PJ25605 T2 2250 Z gt 83 3 5 Ex d A L402 EARPIECE 82150 7250 4 i BLM21 E an y a Woe BLM21 5 E z B 8 PJ25605 T2 s wA 07 C401 C402 C405 C406 C407 R403 o 22pF 10 22pF InF 2 2K TP402 coG XIR XR 50V 16V 16V 50V 16V 5 0402 0402 0402 0402 0402 0402 77 353 7 GND GND GND GND GND 277 SND 43 7V E amp U402 102 LP2982AIM5X 3_0 NOPB m 5 A rm Z V OUT e 54 9 GND 2 E N R405 i 4 C419 lt lt 22K BYPASS ON OFF 2 2uF gt 7 2 GND xs mi 0402 C418 MAOSA M Z 15 417 we lt 10uF XIR E me C409 od 25 Sze VE CONT A OS XSR AN Dev 2 d LDO ON OFF dd T 11B 3 6C 3 7B 5 2B 5 2D 5 8C Eg 2 E E GND MODIFY DATE PATH home users area DESCRIPTION FILE NAME cs1139a cir DAI TELECOM EVK 2 Dai Telecom Group Mod 067 rev 1 11 02 ANNOTATION FORM PROJECT Furlan M 080705 AUDIO A 3 PROJECT SHEET N OF SHEETS DRAWING CODE DRAWN Serdi M 080705 VERIFIED Nonis R 080705 0276 4 5 30276SE11139A
13. and camera is provided by the 24 pads ZIF connector GE864 ZIF 52437 2472 Ball Signal Function Pin Signal C6 CAM SCL IIC SCL O I2C bus serial clock 1 SCLK I GND Ground 2 AGND I MAIN CAM External 2 8V Regulator enable 3 AVDD28 I controlled by CAM PWR ON pin C9 TGPIO 09 CAM RST O Camera Reset 4 RESET N I F8 MONI CAM CLK Clock 5 I GND Ground 6 DGND I 7 8 9 n c l DOUT 0 n c DOUT 1 n c DOUT 2 n c 10 DOUT 3 11 DOUT 4 n c 12 DOUT 5 I O n c 13 DOUT 6 n c 14 DOUT 7 I O n c 15 DOUT 8 n c 16 VCLKOUT O Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 45 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 n c 17 VALIDH O n c 18 VALIDV O VCC_MAIN CAM External 2 8V Regulator enable 19 DVDD28 I controlled by CAM PWR ON pin D7 CAM SDA IIC SDA I O 12 bus serial data 20 SDIN GND Ground 21 PS1 I K11 TGPIO 08 CAM ON Camera power type selector 22 PS2 I GND Ground 23 SHIELD Flash Enable 24 LED_CTRL O Filter the AVDD28 Use
14. asr cam prow 7 sc 7 8 5 8 a 8 ee O E o Ei ry NCC MAIN CAM 9 LI 9 a O 29 E DLA 10 53 119 e R110 Bl 5 O UN ro C 12 amp 12 47K 47K L O Ooo L ds T 1 ze 8 2 1 6402 1 0402 14 pup 5D 6B 14 50105 4 4 7 e O 2 az 52437 2472 EE 381 LA rge JP112 jee 42125 2 1 Lo 82 O JPI05 e XC cau serme so og 17 2 9B MLA 5 Obs AGND on 28 ge 15 5 AvDD28 e UPIUE e wr 2 O ro 5 B 38 axm gt cmm S al gt a E z O Doum TP101 ot TP102 O 24 ILS E lo Powe O O TP103 10 bouts 104 O 11 bouts TP105 p FO 12 m O TP106 tal od 5s 9 13 1 bouts C O TP107 29 ES 29 2 TP108 RE O Dours aas j OF O TP109 4 il 16 _ 17 ae ue Oo 2 TP111 18 VALIDY E O TP112 19 DVDD28 e 2 JPIO8 SDIN id 9 O 21 o PSI 3 2 09 22 Ps2 9B 2 INTERFACE CONNECTORS 24 s un cmi C 50104 LA 4773540102470 1 5
15. component can be useless or can even decrease the power supply performances Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 14 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 e The Bypass low ESR capacitor must be placed close to the Telit GE864 power input pads or in the case the power supply is a switching type it can be placed close to the inductor to cut the ripple provided the PCB trace from the capacitor to the GE864 is wide enough to ensure a dropless connection even during the 2A current peaks e The protection diode must be placed close to the input connector where the power source is drained e The PCB traces from the input connector to the power regulator IC must be wide enough to ensure no voltage drops occur when the 2A current peaks are absorbed Note that this is not made in order to save power loss but especially to avoid the voltage drops on the power line at the current peaks frequency of 216 Hz that will reflect on all the components connected to that supply introducing the noise floor at the burst base frequency For this reason while a voltage drop of 300 400 mV may be acceptable from the power loss point of view the same voltage drop may not be acceptable from the noise point of view If your application doesn t have audio interface but only uses the data feature of the
16. digital input lines working at 2 8VCMOS have an absolute maximum input voltage of 3 75V therefore the level translator IC shall not be powered by the 3 8V supply of the module Instead it shall be powered from a 2 8V 3 0V dedicated power supply This is because in this way the level translator IC outputs on the module side i e GE864 inputs will work at 3 8V interface levels stressing the module inputs at its maximum input voltage This can be acceptable for evaluation purposes but not on production devices NOTE In order to be able to do in circuit reprogramming of the GE864 firmware the serial port on the Telit GE864 shall be available for translation into RS232 and either it s controlling device shall be placed into tristate disconnected or as a gateway for the serial data when module reprogramming occurs Only RXD TXD GND and the On off module turn on pad are required to the reprogramming of the module the other lines are unused All applicator shall include in their design such a way of reprogramming the GE864 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 21 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 An example of level translation circuitry of this kind is Ud 1
17. during calls If we assume that the device stays into transmission for short periods of time let s say few minutes and then remains for a quite long time in idle let s say one hour then the power supply has always the time to cool down between the calls and the heat sink could be smaller than the calculated one for 5 00mA maximum RMS current or even could be the simple chip package no heat sink Moreover in the average network conditions the device is requested to transmit at a lower power level than the maximum and hence the current consumption will be less than the 500mA being usually around 150mA For these reasons the thermal design is rarely a concern and the simple ground plane where the power supply chip is placed can be enough to ensure a good thermal condition and avoid overheating For the heat generated by the GE864 you can consider it to be during transmission 1W max during CSD VOICE calls and 2W max during class10 GPRS upload This generated heat will be mostly conducted to the ground plane under the GE864 you must ensure that your application can dissipate it 3 2 3 Power Supply PCB layout Guidelines As seen on the electrical design guidelines the power supply shall have a low ESR capacitor on the output to cut the current peaks and a protection diode on the input to protect the supply from spikes and polarity inversion The placement of these components is crucial for the correct working of the circuitry A misplaced
18. speaker direct connect imposes the speaker characteristics to be almost exactly the suggested ones otherwise the power output may be reduced if speaker impedance is bigger than 160 or the GE864 ear port may be damaged if speaker impedance is less than 15 2 The other limitation of the speaker direct connection is the power output capability of the GE864 which is limited and for some particular applications may not be enough For these reasons when the power output of the GE864 is not enough or if the speaker characteristics are different from the suggested then it is preferable to use an amplifier to increase the power and current output capabilities Again the output from the GE864 is bridged and both lines should be used where possible as inputs to the power amplifier This ensures a higher common mode rejection ratio reducing the GSM current busts noise on the speaker output In this case the MT lines from the GE864 should be AC coupled with a capacitor of 100nF It is always desirable to have a mute control on the amplifier in order to turn it off while the device is not sending signal to the output in this manner the amplifier background noise which may be audible during idle conditions is cut off A principle schematic may be Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 39 of 60 P Telit GE 864 Telit Hardware User guide Commun
19. this can be made with a capacitor 100nF in series with a resistor 15Q When designing your application remember to provide an adequate bypass capacitor to the amplifier and place it close to the power input pin of the IC keeping the traces as short as possible 7 4 Hands Free earphone low power design The same design considerations made for the handset are valid for the hands free earphone the only difference is that the external ear audio output level from the GE864 is 6dB lower than the internal one so the gain of the amplifier must be 6dB higher to provide the same audio level 7 5 Car Kit speakerphone design For the car kit speaker phone function the power output requirement is usually at least 4W therefore an amplifier is needed to boost the GE864 output The design of the amplifier shall comply with the following guidelines The input to the amplifier MUST be taken from the external audio path EAR EAR_HF of the GE864 because of its echo canceller parameters suited to a car cabin use e The amplifier shall have a gain of 30 40 times 29 32 dB to provide the desired output power of 5 10W with the signal from the GE864 external audio output lines EAR_HF e Ifthe amplifier has a fixed gain then it can be adjusted to the desired value by reducing the input signal with a resistor divider network e The amplifier shall have a mute control to be used while not in conversation This results in two benefits e
20. 0106 C110 4773540103470 ET 2 63V CAM 0603 O JP121 LU 477 a 2 aoe 3 U102 LP2982AIMSX 2 8 NOPB 9 gt 5 Hu R108 C107 TransChip TC5747MF24L 24pin EI o M haie gt 4 3 E E 0 sov 63V vans ON OFF 0402 0402 0603 3B 77 TT LISA C106 C104 C105 MAISA ki pi 8 ws ai SNHLVCIONDCKR M LA R109 E 1 ET 2 15V E 25 0 5 2 e 120 0402 0402 4 U101 i NE gae 77 TI MTI Pp E 7 i lt C S 5 7 77 d Eas ET s AS EG g 53 ce EI VU az al 5 112 5 N vwe 010 ww sxtaverospexn uv E 0402 MODIFY 11 DATE DESCRIPTION PATH home users area I2CBUS DUAL CAMERA FERNAME 1170 cir L DAI TELECOM Dai Telecom Group Mod 067 rev 1 11 02 ANNOTATION men PROJECT Furlan M A 3 PROJECT OF SHEETS DRAWING CODE iu 1060905 5 Draw t vitm 0276 1 1 30276SE11170 TUTTI I DIRITTI RISERVATI RIPRODUZIONE E DIVULGAZIONE ALL RIGHTS RESERVED REPRODUCTION AND DISCLOSURE VIETATE FORBIDDEN En
21. 0U Nn mr ir gu P 4 STPS3L60U 330uF 3300F 20K MEL e A WARNING AN GND 986 50 50 sov 50 con 63V 63V 1 16V When using battery care must be lt 0603 0603 0603 16X16 5 NR e CONT E CONT E 0603 0402 N taken to ensure that the right z 21 polarity is respected 777 Z m d Ei GND GND GND z a GND GND GND GND lt Eas Ea gt 50101 ERE AN RAPC712X e 5 8 8 R115 1 2 5 8 E 9 POWER EE LOK ER JACK se m e RPG 0603 MODIFY 77 7 GND Jakes DATE PATH DESCRIPTION FILE NAME cs1139a cir DAITELECOM Dai Telecom Group OT101 OT102 OT103 Mod 067 rev 1 11 02 ANNOTATION FORM n EN PROJECT Furlan M 080705 POWER REGULATOR BATTERY CHARGE A 3 SHEET OF SHEETS DRAWING CODE DRAWN Serdi M 080705 VERIFIED Nonis R 080705 0276 1 5 30276SE11139A VERIFIED Noms 080705 0276 2 5 30276SE11139A 1 2 3 4 6 8 9 10 11 43 7V PL201 4731955140400 ot 4731955140400 2 y r TX
22. 0uF tantalum capacitor is usually suited Make sure the low ESR capacitor on the power supply output usually a tantalum one is rated at least 10V For Car applications a spike protection diode should be inserted close to the power input in order to clean the supply from spikes A protection diode should be inserted close to the power input in order to save the GE864 from power polarity inversion This can be the same diode as for spike protection example of switching regulator with 12V input is ti9ev input switching regulator 2 560 99 14 INPUT T ceog L202 1DuH 50202 4 3 8V OUTPUT 8 003316 5 WIN mE C2410 a 4 sour SHINY SENSI E Ceo C206 4 1 D203 10v ABE ee sour P STHEi402 R203 fief BND 2 2089 Mark 2 FR SND 4 Baw 1 BnF 200123 a503 CONT E in bu 50 BNO CAI GAD we BND 1204 4 78 Bu Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 11 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 3 2 1 3 Battery Source Power Supply Design Guidelines e The desired nominal output for the power supply is 3 8V and the maximum voltag
23. 1 0300694 Rev ISSUE 2 19 12 05 2 2 Turning OFF the GE864 The turning off of the device can be done in three ways e by software command see GE864 Software User Guide e by hardware shutdown When the device is shut down by software command or by hardware shutdown it issues to the network a detach request that informs the network that the device will not be reachable any more 2 2 1 Hardware shutdown To turn OFF the GE864 the pad ON must be tied low for at least 1 second and then released The same circuitry and timing for the power on shall be used The device shuts down after the release of the ON pad TIP To check if the device has powered off the hardware line PWRCTL should be monitored When PWRCTL goes low the device has powered off 2 3 Hardware Unconditional Reboot To unconditionally Reboot the GE864 the pad RESET must be tied low for at least 200 milliseconds and then released The maximum current that can be drained from the ON pad is 0 15 mA A simple circuit to do it is RESET Unconditional Reboot is impulse Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 7 of 60 Telit 864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 NOTE don t use any pull up resistor on the RESET line nor any totem pole digital output Using pull up resistor may brin
24. 1 0300694 Rev ISSUE 2 19 12 05 3 2 1 Electrical design Guidelines The electrical design of the power supply depends strongly from the power source where this power is drained We will distinguish them into three categories 5V input typically PC internal regulator output 12V input typically automotive Battery 3 2 1 1 5V input Source Power Supply Design Guidelines The desired output for the power supply is 3 8V hence there s not a big difference between the input source and the desired output and a linear regulator can be used A switching power supply will not be suited because of the low drop out requirements When using a linear regulator a proper heat sink shall be provided in order to dissipate the power generated A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the current absorption peaks close to the GE864 a 100uF tantalum capacitor is usually suited Make sure the low ESR capacitor on the power supply output usually a tantalum one is rated at least 10V A protection diode should be inserted close to the power input in order to save the GE864 from power polarity inversion An example of linear regulator with 5V input is 5 input linear regulator 1 1 1 1 1 1 1 1 1 1 1 1 1 3 8V OUT i 1 1 1 5 INPUT A 2 5201 1 IE HINT ce
25. 2 33V HUB 5 45V USB n 2 58 R510 e 5 our VIN 5V_USB a a a a a a S0501 1 5K noMount YES GND USBE 004 292 9 8 amp lz C512 JP501 5 9 PLO 100nF C513 4 BYPASS ON OFF 7 Se ph 2 gleo 9019915102410 tt 10uF N gt c v e E a isi pia v 10V Say 2 E S S8 z CONT A C514 LIA dub 0603 2 ws 2 3 e 1 ppo 24 e 0402 pe 05 3 x 2 23 C 2 Sa DM0 NPINTI 25V 4 QR E RSIT db 3 veces U502 pinto 22 e 0 aus 45V USB 2 H3 C518 A 33 4 RESET TEXTUSB2036VERG4 OCPROTPWRSW a e e 0 5 E x GND 5 mH pps 29 e ssy use 9 5 amp 8 n 82 5 E e S PQFP G32 e Qa n gt EEDATA GANGED DM3 19 o x 77 GND C519 m 8 4 R505 7 18 an R520 100nF GND uza 100K S LL 17 L xs 3 0 USB EB 77 n e BUSPWR PWRON3 e 10V a H GND 5 amp 0402 374 R521 DA 4 4 a 15 a dg 2 gt 5 9 Be of 0402 8 z 5 4 LDO_ON_OFF amp Z jz a SOM nj m 9 1 118 3 6 3 7 4 6 20 8 e pu p E 777 AD 8 8 4 5 noMount YES C502 5 Be EF gt e af x e lt 100nF EMEN a a gt 9 aa Po a gt on 24 T XSR ne s be dg ADBUSO lt lt 0 10V 02 93 x amp 3V30UT AD
26. 3 8 a SOT 0603 ON Orr 2 5 2 98 2 OUT BCR185W R108 Q105 680 596 ae 5 1 0603 gu yy 3 M676 3Fs NN RS s UU Nx Eur e 8 37 BC857B 2 A WARNING LY M676 Q251 26 Q102 EF T Care must be taken to ensure DL101 6 4 e that the right polarity in the R106 m power input is respected Des 2 l Bi Ri 18 amp DO NOT Supply power when the Ad s BCR48PN 7 2 Q101 0402 WTs 8 0 e Battery is not connected 2 S TR2 507 363 E 0402 SOT 323 g 2 9 IBS 1 R107 1 2 2K 2 3 DAZ l 2 3 naw x E ZA GND n lt Q RESET e e e gt LDO_ON_OFF KZ 8 laa 2 4E 2 9C 3 6C 3 7B 4 6E 5 2B 5 2D 5 8C TO Fe GND Z 5 Wen R117 gt aa Oo 5 amp 0402 ij GND PL101 1984617PT1 5_2 3 5 H 2 1 yee H m 2 3 8V M PL105 IN e 1215061 03F 3 1 1 2 5 40 IN 11 2 3 3 8V IN 1 2 Regulator 1215061 03F MH 2 3 Battery PL104 WARNING Care must be taken to ensure D103 that the right polarity in the STPS140Z power input is respected SOD123 7 A GND FUSE 1206 1 107 1984617 1 5_2 3 5 BATTERY LI ION l 3 7V Li Ion Nominal 720105 77 max voltage 4 2V Li Ion Oll 500123 LM2596S ADJ NOPB ENT suggested capacity 1000mAh MIN 5V EDU e e L fevn vour 2 e e al 2 5 4 7407727 ON OFF FBACK m ioi C101 02 C103 C104 cu 2 Sio C106 C107 R114 C108 A H7 cl STPS3L6
27. 3v 207 SS0P 24 mu m rc ox oO 10 10 vee LB ZIA o eo Xo O o ra 12 11 4 Ci v ma Oo 13 e r a 25 m x u oy 42 c O B 14 15 Cen y oa m Bas O 77 7 2 GND dcd_uart T1 IN T4 OUT DCD RS232 5 3 tx uart O 4 T2 1N T2 QUT gt TX RS23 18 1 dsr uart 2 34 13 IN TAS_OUT gt DSA_AS292 18 24 cts_uart 0 4 14 14 T4 QUT CTS R5232 21 20 ri uart 5 4 15_ IN T5_OUT RI HS239 5 4 lt P1 0UT lt BRx R8232 22 23 rts uart C R2 0UT R18 R8232 17 15 dtr_uart lt ASIN DTR RS238 GND B B END the RS232 serial port lines are usually connected to a DB9 connector with the following layout DCD_AS232 DSA_AS232 OC TX RS232 a Cm RTS RS232 D RX RS232 C CTS_AS232 OTR_AS232 lt _ Ols RI_AS232 C OQ Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 22 of 60 Telit GE864 Telit Hardware User guide 1vv0300694 Rev ISSUE 2 19 12 05 Communications S p A 5 2 5V UART level translation If the OEM application uses a microcontroller with a serial port UART that works at a voltage different from 2 8 3V then a circuitry has to be provided to
28. 6 n 1 les vec _8 5 BCBUS2 ApBusa a 2 nca x 9 Us MS 3 BUS3 2 USBDP ADBUSS 45V USB 3 lot VPEA BCBUS3 m 5 e LT YE si 26 J 2 ga ADBUSG 7 R536 e 5 I WUB 5 16 E RSTOUT ADBUS7 vus 42 8 R538 HL o 3 257 za 2 4 RESET EE 77 48 5 ey fe ue REN TP516 RA noMount YES Acon 15 SND 2 5 lt o o o XTIN_FT2232 o gt XTIN ACBUS1 H n 5 9 EX 05848 AcBusa H gt 29 JP504 H GND 4 mS LDO_ON_OFF 24 SUWUA 10 3 6C 3 7B 4 6E 2B 8C E a B 1 11B 3 6C 3 7B 4 6E 2B 8C 48 EECS 117503 er 5 FT2232L 4 RX PROG USB 2 LOFP48 BDBUS 32 PROG USB 55 5 ae aai USBI lt gt TRACE SSC AN ST BDBUS2 zR TP532 e nu 2 ES 533 e GND BDBUS4 TP534 gt 5 55 t 33 Do 2 256 33 44 7 0 45V USB See les 32C MODIFY BDBUS7 22 lt RLUSB 32 R501 0501 18K 93LC56B_I SNG AUS Bcbuso 39 29 5 8 BCBUS1 0402 63 Mss 28 PATH home users area DESCRIPTION Ay 1 BCBUS2 ok a CLK NC 7L 2 8 412 04 5 6 BCBUS3 TP531 e 5 DI NC6 FILE NAME cs1139a 15 26 DAI TELECOM DO vss Dai Telecom Group ie Mod 067 rev 1 11 02 ANNOTATION FORM du o 2 9 OO 505 a 583 2 Pl e PROJECT Furlan M 080705 USB lt gt PROG
29. BUS1 23 SSCO MTSR uz y E SS 2 5 2 4B E ADBUS2 22 ssco_MRST g 8 i 248 GND USBDM ADBUS3 S RE ApBusa H 5 g 7 0 ApBUss H Eos 8 94 ADBUs H7 R506 R509 R514 s ovr 16 R522 R523 evum Eg RSTOUT ADBUS 15K 15K 15K 15K ie R526 zi 4 x s RESET 5 5V_USB EL 5 5 5 5 noMount YES 22415 GND 0402 0402 0402 0402 one ACBUSO XTIN FT2232 43 13 USB H B 3 x XTIN ACBUSI U alles GND GND GND GND 5 75 ACBUS2 4 JP503 ACBUS3 H LDO_ON_OFF xrour suwua H 1 11B 3 6C 3 7B4 6E 2B 2D 45V USB 48 EECS U509 2 E e Zak 2 1 EESK FT2232L BpBuso H ee 8 TRACE USB TET 9 C506 GENEE 2 kEDATA LOFP48 BDBUSI 9 _rx_TRACE_USB 3 U505 PUSR zm Boe 100nF 3 0V_USB SES BDBUs2 2 XS LP2981AIMS5X 3 0 NOPB GND 526 H3 BDBUS3 37 5 TT 1 our VIN TP527 GND BDBUS4 25 VAN l S a C509 C510 GND 528 e BDBUSS 25 GND i 100nF E 8 oo 5 8 XSR 10uF 4 ON OFF 6 33 2 9g 10V 10 63V 35V USB CONT A 132 a ER gt gt ul 24 1IC_SCL_HW 0402 0603 BDBUS7 E ESO ADBUSO lt 6 avaoUT ADBUsi1 2 SDA HW db R524 U507 4B GND 18K 93LCS6B I SNG Buso S ApBUs2 22 db m 5V_USB 5 p 5 BCBUSI Ba 2 JP50
30. D DTR GND DSR RTS CTS RI GND Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 20 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 5 1 RS232 level translation In order to interface the Telit GE864 with a PC com port or a RS232 EIA TIA 232 application a level translator is required This level translator must invert the electrical signal in both directions change the level from 0 3V to 15 15V Actually the RS232 UART 16450 16550 16650 amp 16750 chipsets accept signals with lower levels on the RS232 side EIA TIA 562 allowing for a lower voltage multiplying ratio on the level translator Note that the negative signal voltage must be less than and hence some sort of level translation is always required The simplest way to translate the levels and invert the signal is by using a single chip level translator There are a multitude of them differing in the number of driver and receiver and in the levels be sure to get a true RS232 level translator not a RS485 or other standards By convention the driver is the level translator from the 0 3V UART level to the RS232 level while the receiver is the translator from RS232 level to 0 3V UART In order to translate the whole set of control lines of the UART you will need 5 driver 3 receiver NOTE The
31. ION FORM PROJECT Furlan M 080705 UART A 3 DRAWN Sia 080705 PROJECT SHEET N OF SHEETS DRAWING CODE erdi M VERIFIED Nonis R 080705 0276 3 5 30276SE11139A 2 3 4 3 6 9 10 11 te Ze e noMount YES E E 5 Zo og e e noMount YES noMount YES m IN 0401 n JP403 C LM4862MX NOPB t a9 PLAOI 255 5 AUDIO Switch a 9019915102410 s xL e wows 25 878 4 gt El 5 WAZ SHUTDOWN Ss 8 7 gt PL402 PL403 PL404 g a e vex BYPASS 1215061 05F 1215061 05F 1215061 05F 3 A lt Q C403 C404 7 IN i e 1 1 d 100nF 100nF e e OF T amp m uv S E Le STI 2 e EAR_HF 5 E 0603 0603 og le GND 3 e e a2 C408 g 8 da 100nF i xi 4 noMountz YES 5 5 amp
32. N Power ON impulse bod M y FD NOTE don t use any pull up resistor on the line it is internally pulled up Using pull up resistor may bring to latch up problems on the GE864 power regulator and improper power on off of the module The line ON must be connected only in open collector configuration NOTE In this document all the lines that are inverted hence have active low signals are labeled with a O name that ends with a or with a bar over the name NOTE The GE864 turns fully on also by supplying power to the Charge pad provided there s a battery on the VBATT pads Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 5 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 For example 1 Let s assume you need to drive the ON pad with a totem pole output of a 3 5 V microcontroller uP OUTI 3 5g 02 507 323 Fs 13 5 Vo m EE 5 E 0402 Power ON OFF inpulse e GND 2 Let s assume you need to drive the ON pad directly with an ON OFF button OND Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 6 of 60 Telit GE864 Telit Hardware User guide Communications S p A
33. TRACE rx TRACE ga VBATT TRACE oT RX_TRACE RX TRACE Le VBATT 9 2 SDA HW 4 i 0402 NES vearr a9 IIC GND 5 3 VBATT 59 IIC SCL HW 6 R202 a s e 2 a gt 5 Az 58 0 2 0402 gt sco Ran 8 R203 2 5 ae 7 5 7 a SSC SSCO MTSR 0402 SSCO_MTSR ee GND lt o 5 11B 2 L 55 0 MRST 5 2 sco Mist e gt e GND S 11B x cider CHARGE CFR GND n ee CHARGE Le AR GND GND 3 5 lt g GND e Le GND E GND GND 15 aa n PES E dM kam CIO4 RXD LO RM RXD ON OFF 21 C103 TXD Ci03 TXD 3 3 C108 DTR CIOS DTR RESET M RESET 9 3 3C 1 9 4 18 lt 0 Le E 20 19 N lt CIO7 DSR C c1o7 pse e 3 2 a lt CIOS RTS C105 RTS 20 lo 3 3 C106 CTS 2 gt CI06 CTS STAT LED lt 2 STAT LED 3 3 C125 RING 2 CI25RING le 24 3 3C e 25 24 GND le j 25 GND 27 26 GND Le GND 2 e e l a 2 GND 8 3 3 5 4 E 2 gt EAR_HF E qn C GND EAR a e 5 2 EAR_MT M C EAR MT S0201 m e EAR HF gt EAR HF FMS006Z 2001 0 d 4 11B EAR_MT gt EAR MT e e SIMIO 5 JAXE 3 SIMCLK 5 SIMCLK uw 4 11B MIC_HF SIM CA amp D 7 SIMRST e z SIMRST a 35 4 1 1B SIMVCC 3 wn l
34. TRACE I2C SSC A3 lt o 8 PROJECT SHEET N OF SHEETS DRAWING CODE USBO lt gt PROG I2C DRAWN Sera M 080709 0276 5 5 302765 39 VERIFIED Nonis R 080705 27 7 111 1vv0300694 Rev ISSUE 2 19 12 2005 Z lent Annex B Camera EVB schematics Reproduction forbidden without Telit Communication written authorization All Right reserved Right of modification reserved page 57 of 60 2 4 6 7 8 9 10 11 a S gt bi 53 aR SO101 SO102 4779723130417 4779723130417 C E tle ally P 2 2 mme 32 2 6B 5 e CAM SYNC AGILENT ES E lc TCS747MF24L FA e 58 01010 Se A 5 10 8 Gla 20 cao pE 6 3b 6 gt Toro mci
35. Telit GE864 then this noise is not so disturbing and power supply layout design can be more forgiving e The PCB traces to the GE864 and the Bypass capacitor must be wide enough to ensure no significant voltage drops occur when the 2A current peaks are absorbed This is for the same reason as previous point Try to keep this trace as short as possible e The PCB traces connecting the Switching output to the inductor and the switching diode must be kept as short as possible by placing the inductor and the diode very close to the power switching IC only for switching power supply This is done in order to reduce the radiated field noise at the switching frequency 100 500 kHz usually e The use of a good common ground plane is suggested e The placement of the power supply on the board should be done in such a way to guarantee that the high current return paths in the ground plane are not overlapped to any noise sensitive circuitry as the microphone amplifier buffer or earphone amplifier e The power supply input cables should be kept separate from noise sensitive lines such as microphone earphone cables Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 15 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 4 Antenna The antenna connection and board layout design are the most important par
36. UIREMENTS Impedance 50 ohm Max Attenuation 0 3 dB No coupling with other signals allowed Cold End Ground Plane of antenna shall be equipotential to the GE864 ground pins Furthermore if the device is developed for the US market and or Canada market it shall comply to the FCC and or IC approval requirements This device is to be used only for mobile and fixed application The antenna s used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter End Users must be provided with transmitter operation conditions for satisfying RF exposure compliance OEM integrators must ensure that the end user has no manual instructions to remove or install the GE864 module Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed operating configurations 4 2 Antenna PCB line Guidelines e Ensure that the antenna line impedance is 50 ohm e Keep the antenna line on the PCB as short as possible since the antenna line loss shall be less than 0 3 dB e Antenna line must have uniform characteristics constant cross section avoid meanders and abrupt curves e Keep if possible one layer of the PCB used only for the Ground plane e Surround on the sides over and under the antenna line on PCB with Ground avoid having other signal tracks facing directly the ant
37. a Buffer between module clk out MONI CAM and camera clk in IN n c Not connected pete as msh zal shaspas 2 Camera Socket Connector 0 1 gt gt Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 46 of 60 Telit GE864 Telit Hardware User guide 1vv0300694 Rev ISSUE 2 19 12 05 Communications S p A 9 1 2EVB for Transchip camera support In order to interface the Telit GE864 module with a CMOS camera Telit has developed an evaluation board see Annex B The EVK2 see Annex A allow connecting all Telit modules through 2 connectors of 40 pins each The I2CBUS CAMERA board is plugged in the 2 connectors of 30 pins each on the module board CAMERA BOARD MODULE BOARD MAIN BOARD ELVA Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 47 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 9 1 3Example usage script for camera Camer
38. a setting shown here are the defaults ones gt AT CAMSEL 0 camera selection 0 auto 2 transchip OK gt AT CMODE 0 camera mode 0 day 1 night OK gt 0 camera quality 0 low 1 medieum 2 high OK gt AT CAMRES 0 camera resolution 0 VGA 1 QVGA 2 QQVGA OK gt AT CAMCOL 0 camera color 0 color 1 grayscale OK gt AT CAMZOOM 0 camera zoom 0 x1 1 x2 2 x4 OK gt 0 camera timestamp 0 1 time only 2 data only 3 time amp data OK Taking an reading a photo gt 1 OK gt AT TPHOTO take photo OK gt AT OBJL see photo dimension OBJL Snapshot 38900 where 38900 is the file dimension in bytes of the photo taken OK gt AT RPHOTO download the photo sa df us where data Correspond to the photo data in binary OK gt AT TPHOTO OK gt AT RPHOTO Repeating photo capture and download n times gt AT CAMEN O camera OFF Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 48 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 10 Conformity Assessment Issues The GE864 module is assessed to be conform to the R amp TTE Directive as stand alone products so If the module is installed in conformance with Dai Telecom installation instructions require no further evaluat
39. abni ki aplikaciji bo morala upo tevati projektna navodila opisana v tem priro niku SP La utilizaci n del modulo GSM GPRS GE864 debe ser conforme a los usos para los cuales ha sido dise ado descritos en este manual del usuario FR L int gration du module cellulaire GE864 GSM GPRS dans l application de l utilisateur sera faite selon les r gles de conception d crites dans ce manuel HE manen 1 03 onan 90 PAPRA TYAN 2002 mewmsaag neni nv WPN mumopwa nasm GE864 The information presented in this document is believed to be accurate and reliable However no responsibility is assumed by Telit Communication for its use nor any infringement of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under any patent rights of Telit Communication other than for circuitry embodied in Telit products This document is subject to change without notice Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 4 of 60 Telit GE864 Telit Hardware User guide 1vv0300694 Rev ISSUE 2 19 12 05 Communications S p A 2 Hardware Commands 2 1 Turning ON the GE864 To turn on the GE864 the pad ON must be tied low for at least 1 second and then released The maximum current that can be drained from the ON pad is 0 1 mA A simple circuit to do it is O
40. adapt the different levels of the two set of signals As for the RS232 translation there are a multitude of single chip translators but since the translation requires very few components then also a discrete design can be suited For example a possible inexpensive translator circuit for a 5V driver can be T5V vCC 4 5 6 TR4 T K xz BCR22PN S EN b WPS 501 363 3 2 1 TO TxD sy Ce FROM OEM GM862 HARDWARE R7 TXD 3v 47K 5 CR10 and for a 5V receiver C103 TXD lS 1 PWROTL H1 ATK BA BCR22PN C403 1xD 2 Bv WPS 507 363 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 23 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 NOTE The UART input line TXD rx uart of the GE864 is NOT internally pulled up with resistor so there may be the need to place an external 47KQ pull up resistor either the DTR dtr_uart and RTS rts_uart input lines are not pulled up internally so an external pull up resistor of 47KQ may be required A power source of the internal interface voltage corresponding to the 2 8VCMOS high level is available at the VAUX pad whose absolute maximum output current is 100mA Pull up resistors can be connected to the VAUX pad provided t
41. aming 50 dB 1 300 times at minimum voice level talker whispering For the handsfree car kit microphone the voice attenuation due to the distance between the microphone and the talker must be taken into account when designing the microphone amplifier For a car cabin usually the distance between the talker and the mic is about 50cm in these conditions the attenuation can be considered as a thumb rule around 20dB Another thing to consider especially for cabin car use is the fact that the external mic will pick up also ambient noise to overcome this problem it is preferable to set the gain of the microphone 10dB lower with respect to the calculated value for a nominal sensitivity The corresponding reduction in signal level will be compensated by an increased voice volume of the talker which will speak louder because of the ambient noise Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 26 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 For the headset we shall distinguish two different types the headsets having the microphone sustained close to the mouth and the headsets having the microphone on the earpiece cable The same considerations for the additional voice attenuation due to the distance from the microphone and the noise pick up can be made for the headset having the mic
42. ations S p A 1 0300694 Rev ISSUE 2 19 12 05 high power external ear e line coupling DC e line type bridged not referred to GND e speaker impedance operating conditions 240 minimum load impedance 49 e signal bandwidth 150 8000 Hz 3 dB maximum power output 6W e THD N 10 6W 7 2 General Design rules There are several configurations for the audio output path but the various design requirements can be grouped into three different categories e handset earphone low power typically a handset e hands free earphone low power typically a headset e car kit speakerphone high power typically a speaker The three groups have different power requirements usually the first two applications need only few mW of power which can be directly drained from the GE864 pads provided a suited speaker is used This direct connect design is the cheaper and simpler solution and will be suited for the most of the earphone design requirements There s no need to decouple the output ear lines if a suited earpiece is connected For the last group the speakerphone a power amplifier is required to raise the output power up to 5 10W required in a car cabin application All the designs shall comply with the following guidelines e Where possible use a bridged earphone circuitry to achieve the maximum power output from the device e Keep the earphone traces on the PCB and wires as short as possible e If your applicat
43. ce rety 3n iE R202 10uF 47 fae ETE CONTE FER i Gh sin 1 1 END END d 1 1 I 0803 1 1 oe i END 1 1 1 dmm ias dh dae dh ee 4 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 10 of 60 Telit GE 864 7 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 3 2 An 1 2 12V input Source Power Supply Design Guidelines The desired output for the power supply is 3 8V hence due to the big difference between the input source and the desired output a linear regulator is not suited and shall not be used A switching power supply will be preferable because of its better efficiency especially with the 2A peak current load represented by the GE864 When using a switching regulator a 500kHz or more switching frequency regulator is preferable because of its smaller inductor size and its faster transient response This allows the regulator to respond quickly to the current peaks absorption For car PB battery the input voltage can rise up to 15 8V and this should be kept in mind when choosing components all components in the power supply must withstand this voltage A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the current absorption peaks a 10
44. document is the description of some hardware solutions useful for developing a product with the Telit GE864 module In this document all the basic functions of a mobile phone will be taken into account for each one of them a proper hardware solution will be suggested and eventually the wrong solutions and common errors to be avoided will be evidenced Obviously this document can not embrace the whole hardware solutions and products that may be designed The wrong solutions to be avoided shall be considered as mandatory while the suggested hardware configurations shall not be considered mandatory instead the information given shall be used as a guide and a starting point for properly developing your product with the Telit GE864 module For further hardware details that may not be explained in this document refer to the Telit GE864 Product Description document where all the hardware information is reported NOTICE EN The integration of the GE864 GSM GPRS cellular module within user application shall be done according to the design rules described in this manual IT L integrazione del modulo cellulare GSM GPRS GE864 all interno dell applicazione dell utente dovr rispettare le indicazioni progettuali descritte in questo manuale DE Die Integration des GE864 GSM GPRS Mobilfunk Moduls in ein Ger t mu gem der in diesem Dokument beschriebenen Konstruktionsregeln erfolgen SL Integracija GSM GPRS GE864 modula v upor
45. e allowed is 4 2V hence a single 3 7V Li Ion cell battery type is suited for supplying the power to the Telit GE864 module The three cells Ni Cd or Ni MH 3 6 V Nom battery types or 4V PB types MUST NOT BE USED DIRECTLY since their maximum voltage can rise over the absolute maximum voltage for the GE864 and damage it NOTE DON T USE any Ni Cd Ni MH and Pb battery types directly connected with GE864 Their use can lead to overvoltage on the GE864 and damage it USE ONLY Li lon battery types e A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the current absorption peaks a 100uF tantalum capacitor is usually suited Make sure the low ESR capacitor usually a tantalum is rated at least 10V e A protection diode should be inserted close to the power input in order to save the GE864 from power polarity inversion Otherwise the battery connector should be done in a way to avoid polarity inversions when connecting the battery The battery capacity must be at least 5 00mAh in order to withstand the current peaks of 2A the suggested capacity is from 500mAh to 1000mAh 3 2 1 4 Battery Charge control Circuitry Design Guidelines The charging process for Li Ion Batteries can be divided into 4 phases Qualification and trickle charging e Fast charge constant current e Final charge constant voltage or pulsed charging e Maintenance charge The qualification process consists in a batt
46. ed page 36 of 60 Z Telit Communications S p A Telit GE 864 Hardware User guide 1vv0300694 Rev ISSUE 2 19 12 05 external speaker EAR_HF EAR_HF line coupling line type e speaker impedance operating conditions minimum load impedance e signal bandwidth e maximum differential output e rated output power e maximum power output e volume level steps SW e number of volume steps SW The EVK2 v 1 2 audio output characteristics are internal external ear single ended e line coupling e line type e speaker impedance operating conditions minimum load impedance e signal bandwidth maximum output e maximum power output e THD N internal external ear bridged line coupling e line type e speaker impedance operating conditions e minimum load impedance e signal bandwidth maximum output e maximum power output e THD N DC bridged gt 16 15 1kHz 150 150 8000 Hz 3 dB 425 mVims 2 5 mW 7 5 mW 2dB 10 AC single ended referred to GND 280 80 150 8000 Hz 3 dB 800 mV 80 mW 8 2 1 80mW DC bridged not referred to GND 280 80 150 8000 Hz 3 dB 1 6 Vims 320mW 8 Q 1 330mW Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 37 of 60 Telit GE864 Telit Hardware User guide Communic
47. enna line track e The ground around the antenna line on PCB has to be strictly connected to the Ground Plane by placing vias once per 2mm at least e Place EM noisy devices as far as possible from GE864 antenna line Keep the antenna line far away from the GE864 power supply lines e Ifyou have EM noisy devices around the PCB hosting the GE864 such as fast switching ICs take care of the shielding of the antenna line by burying it inside the layers of PCB and surround it with Ground planes or shield it with a metal frame cover If you don t have EM noisy devices around the PCB of GE864 by using a strip line on the superficial copper layer for the antenna line the line attenuation will be lower than a buried one Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 17 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 4 3 Antenna installation Guidelines e Install the antenna in a place covered by the GSM signal e The Antenna must be installed to provide a separation distance of at least 20 cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter e Antenna shall not be installed inside metal cases e Antenna shall be installed also according Antenna manufacturer instructions Reproduction forbidden without written authoriza
48. ery voltage measure indicating roughly its charge status If the battery is deeply discharged that means its voltage is lower than the trickle charging threshold then the charge must start slowly possibly with a current limited pre charging process where the current is kept very low with respect to the fast charge value the trickle charging During the trickle charging the voltage across the battery terminals rises when it reaches the fast charge threshold level the charging process goes into fast charge phase During the fast charge phase the process proceeds with a current limited charging this current limit depends on the required time for the complete charge and from the battery pack capacity During this phase the voltage across the battery terminals still raises but at a lower rate Once the battery voltage reaches its maximum voltage then the process goes into its third state Final charging The voltage measure to change the process status into final charge is very important It must be ensured that the maximum battery voltage is never exceeded otherwise the battery may be damaged and even explode Moreover for the constant voltage final chargers the constant voltage phase final charge must not start before the battery voltage has reached its maximum value otherwise the battery capacity will be highly reduced Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification r
49. eserved page 12 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 The final charge can be of two different types constant voltage or pulsed GE864 uses constant voltage The constant voltage charge proceeds with a fixed voltage regulator very accurately set to the maximum battery voltage and hence the current will decrease while the battery is becoming charged When the charging current falls below a certain fraction of the fast charge current value then the battery is considered fully charged the final charge stops and eventually starts the maintenance The pulsed charge process has no voltage regulation instead the charge continues with pulses Usually the pulse charge works in the following manner the charge is stopped for some time let s say few hundreds of ms then the battery voltage will be measured and when it drops below its maximum value a fixed time length charging pulse is issued As the battery approaches its full charge the off time will become longer hence the duty cycle of the pulses will decrease The battery is considered fully charged when the pulse duty cycle is less than a threshold value typically 10 the pulse charge stops and eventually the maintenance starts The last phase is not properly a charging phase since the battery at this point is fully charged and the process may stop after the final charge The maintenance charge provides an additional c
50. g to latch up problems on the GE864 power regulator and improper functioning of the module The line RESET must be connected only in open collector configuration TIP The unconditional hardware reboot should be always implemented on the boards and software should use it as an emergency exit procedure For example 1 Let s assume you need to drive the RESET pad with a totem pole output of a 3 5 V microcontroller uP OUT2 RESET 4 02 125 375 D MN c 1 M M NEM Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 8 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 3 Power Supply The power supply circuitry and board layout are a very important part in the full product design and they strongly reflect on the product overall performances hence read carefully the requirements and the guidelines that will follow for a proper design 3 1 Power Supply Requirements The GE864 power requirements are Nominal Supply Voltage 3 8 V Max Supply Voltage 4 2V e Supply voltage range 34V 42V e Max Peak current consumption impulsive 1 9 e Average current consumption during GPRS transmission rms 500 mA e Max Average current consum
51. gnetic Compatibility Standards FCC47 Part 15 To meet the FCC s RF exposure rules and regulations The system antenna s used for this transmitter must be installed to provide a separation distance of at least 20 cm from all the persons and must not be co located or operating in conjunction with any other antenna or transmitter The system antenna s used for this module must not exceed 3 dBi for mobile and fixed or mobile operating configurations Users and installers must be provided with antenna installation instructions and transmitter operating conditions for satisfying RF exposure compliance Manufacturers of mobile fixed or portable devices incorporating this module are advised to clarify any regulatory questions and to have their complete product tested and approved for FCC compliance Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 49 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 Document Change Log Revision Date Changes ISSUE 0 18 10 05 First release ISSUE 1 22 11 05 Added notice on page 4 ISSUE 2 19 12 05 Added Paragr 10 Conformity Assessment Issues Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 50 of 60 Teli
52. harging process to compensate for the charge leak typical of a Li Ion battery It is done by issuing pulses with a fixed time length again few hundreds of ms and a duty cycle around 5 or less This last phase is not implemented in the GE864 internal charging algorithm so that the battery once charged is left discharging down to a certain threshold so that it is cycled from full charge to slight discharge even if the battery charger is always inserted This guarantees that anyway the remaining charge in the battery is a good percentage and that the battery is not damaged by keeping it always fully charged Li Ion rechargeable battery usually deteriorate when kept fully charged Last but not least in some applications it is highly desired that the charging process restarts when the battery is discharged and its voltage drops below a certain threshold GE864 internal charger does it As you can see the charging process is not a trivial task to be done moreover all these operations should start only if battery temperature is inside a charging range usually 5 C 45 C The GE864 measures the temperature of its internal component in order to satisfy this last requirement it s not exactly the same as the battery temperature but in common application the two temperature should not differ too much and the charging temperature range should be guaranteed NOTE For all the threshold voltages inside the GE864 all threshold are fixed in order to ma
53. hat the pulled up lines are GE864 input lines connected to open collector outputs in order to avoid latch up problems on the GE864 Care must be taken to avoid latch up on the GE864 and the use of this output line to power electronic devices shall be considered with care especially for devices that generate spikes and noise such as level translators digital ICs or microcontroller failure in any of these condition can severely compromise the GE864 functionality NOTE The input lines working at 2 8VCMOS can be pulled up with 47KQ resistors that can be connected directly to the VAUX line NO disturbing devices should be powered with the VAUX line otherwise the module functionality may be compromised Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 24 of 60 Z Telit Communications S p A Telit GE 864 Hardware User guide 1vv0300694 Rev ISSUE 2 19 12 05 6 Microphone The microphone circuitry is the more noise sensitive and its design and layout must be done with particular care 6 1 Microphone line Characteristic and requirements The Telit GE864 provides two audio paths for the microphone and the earpiece the internal and the external audio paths Only one of the two paths can be active at a time and it is selectable by hardware line AXE or by AT command The audio characteristics of the two paths are slightly different a
54. he microphones have a hot wire were the positive biasing must be connected usually it is indicated by a sign or a red point If the polarity of the bias is reversed then the microphone will not work properly For this reason be sure to respect the mic biasing polarity _ M LLL MA M Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 28 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 6 3 1 Balanced Microphone biasing The balanced microphone bias voltage should be obtained from a dedicated voltage regulator in order to eliminate the noise present on the power lines This regulator can be the same for all the audio paths The microphone should be supplied from a capacitor multiply circuit For example a circuit for the balanced microphone biasing can be 3 8V 3V MIC MIC Biasing Regulator Capacity multiply circuit M SND MICH lt 1 i 1 To MIC Buffer amplifier C MK 1 MIC lt 1 1 R3 Wee cee 0402 NOTE the balanced application the resistors R2 and must have the same value to keep the circuit balanced O NOTE
55. ications S p A 1vv0300694 Rev ISSUE 2 19 12 05 EAR_MTt EAR MT 100nF The resulting gain and high pass cut can be obtained with the formula Gain R2 1 freq And an example of internal Ear amplifier is INTERNAL EAR AMPLIFIER C803 10pF H 1 H 1 f 1 1 1 1 1 H 1 1 t 1 H 1 H 1 1 0801 1 LM4662M 2 c i 27 747 on SZ 58 TO SPEAKER 4 B hop n L4 ape 9381195 EAR 4 5 vo SHUTDONN a z 84 m ics FROM GM862 EAR Ct T BYPASS LI EPIS 1 2 7 Jeno mela 1 28 AGOnF 400nF i 1Bv 16v 1 P vv 0603 9603 Jev un Cane H 0603 PL803 i EN 12180 1 03 0803 1 1 ABO RBOG6 6 1 ie fae 7 77 77 2 MUTE CONTROLLED END e H 5 a ALWAYS ON H H e GND i GAD AMPLI POWER CONTROL 1 Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 40 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 Some amplifier require a low impedance load at high frequency in order to avoid auto oscillation
56. ion requires a single ended earpiece and you want a direct connection then leave one of the two output lines open and use only the other referred to ground Remember that in this case the power output is 4 times lower than the bridged circuit and may not be enough to ensure a good voice volume e Make sure that the earphone traces in the PCB don t cross or run parallel to noisy traces especially the power line e The cable to the speaker shall be a twisted pair with both the lines floating for the bridged output type shielded with the shield to ground for the single ended output type Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 38 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 7 2 1 Noise Filtering The I O of the PCB should have a noise filter close to the connector to filter the high frequency GSM noise The filter can be a II of 2 capacitor and a inductance with the one capacitor of 39pF 0603 case and the other capacitor of 1 0603 the inductance shall have a value of 39uH 7 3 Handset earphone design As seen previously 160 speaker can be directly connected to the output pads MT and EAR MT of the GE864 This solution is often the more cost effective reducing the components count to a minimum There are several limitations to the use of this solution
57. ion under Article 3 2 of the R amp TTE Directive and do not require further involvement of a R amp TTE Directive Notified Body for the final product In all other cases or if the manufacturer of the final product is in doubt then the equipment integrating the radio module must be assessed against Article 3 2 of the R amp TTE Directive In all cases assessment of the final product must be made against the Essential requirements of the R amp TTE Directive Articles 3 1 a and b safety and EMC respectively and any relevant Article 3 3 requirements The GE864 module is conform with the following European Union Directives e R amp TTE Directive 1999 5 EC Radio Equipment amp Telecommunications Terminal Equipments e Low Voltage Directive 73 23 EEC and product safety e Directive 89 336 EEC for conformity for EMC In order to satisfy the essential requisite of the R amp TTE 99 5 EC directive the GE864 module is compliant with the following standards e GSM Radio Spectrum Standard EN 301 511 and 3GPP 51 010 1 e EMC Electromagnetic Compatibility Standards EN 301 489 1 and EN 301 489 7 e LVD Low Voltage Directive Standards EN 60 950 In this document and the Hardware User Guide Software User Guide all the information you may need for developing a product meeting the R amp TTE Directive is included The GE864 module is conform with the following US Directives e Use of RF Spectrum Standards FCC 47 Part 24 GSM 1900 e EMC Electroma
58. level on the input pads of the internal mic of the GE864 is 24 dB 15 times higher than the microphone output and therefore the buffer has to gain 24 dB The corresponding values for the resistors on the buffer could be if we keep the input resistance 10kQ R604 R606 gain R603 gain R605 15 10 150 kQ The commercial values of 150kQ amp 10kQ are then chosen As a consequence the values of the capacitors C636 and C637 shall be C636 C637 1 2n 8000 R606 132 10 F A commercial value of 100pF is then chosen Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 32 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 6 4 2 Buffered Unbalanced Single Ended Mic A sample schematic for a buffered unbalanced single ended microphone can be SINGLE ENDED MICROPHONE BUFFER 10 dB 434 EXT SINBLE D 3V EXT MIC SINGLE ES qq SES R714 4 o8 47K GND 0693 1701 153491210 2 m 8 5 DECOUPLING CAPACITORS Ou am ap SIRS gt Be H icto E EAA EE 3 m 4 See S286 5 C719 R716 tie o m 10DnF 47 99 m 2
59. liminating the background noise when not in conversation and saving power e The power to the amplifier should be decoupled as much as possible from the GE864 power supply by either keeping separate wires and placing bypass capacitors of adequate value close to the amplifier power input pads e The biasing voltage of the amplifier shall be stabilised with a low ESR e g a tantalum capacitor of adequate value NOTE The GE864 audio path connected to the car kit hands free amplifier MUST be the external one EAR_HF otherwise the echo cancellation will not be done due to the difference in the echo canceller characteristics of the GE864 internal audio path from the external audio path Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 41 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 An example of car kit amplifier schematic can be HIGH POWER EXT EAR AMPLIFIER 1 1 1 1 1 1 0904 1 TOABS4AISF hi 2 ET m 1 ejje T JE ARF na 6913 agog SPEAKER 41 The 18 4 lus BOHM na Sv TL x 1 me in i 1 i lt Ss E 1 E4R HF 4 i MODE
60. ly improve the autonomy of the device 8 4 Using the Buzzer Output GPIO 07 BUZZER The GPIO_07 BUZZER pad when configured as Buzzer Output is controlled by the GE864 module and will drive with appropriate square waves a Buzzer driver This permits to your application to easily implement Buzzer feature with ringing tones or melody played at the call incoming tone playing on SMS incoming or simply playing a tone or melody when needed by your application A sample interface scheme is included below to give you an idea of how to interface a Buzzer to the GPIO_07 BUZZER Q102 ser BZ101 SOT 23 SMUS 1227 SMBT2907A O NOTE To correctly drive a buzzer a driver must be provided its characteristics depend on the Buzzer and for them refer to your buzzer vendor Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 44 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 9 Camera 9 1 Camera characteristics The GE864 module provides a direct support for digital cameras with the following characteristics Type TRANSCHIP TC5747 Technology CMOS COLOR camera Max picture size VGA 480x640 pixels landscape Output format JPEG Sensitivity 4 Lux 9 1 1 Camera interface connectors The interface connection between GE864
61. mpatible with the 2 8V CMOS levels of the GPIO If the digital output of the device to be connected with the GPIO input pad has interface levels different from the 2 8V CMOS then it can be connected to GPIOI or can be buffered with an open collector transistor provided a 47KQ pull up resistor is connected as seen in the paragraph 5 2 5V UART Level translation 8 2 Using a GPIO pad as OUTPUT The GPIO pads when used as outputs can drive 2 8V CMOS digital devices or compatible hardware When set as outputs the pads have a push pull output and therefore the pull up resistor may be omitted Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 43 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 8 3 Using the Alarm Output GPIO 06 ALARM The GPIO 06 ALARM pad when configured as Alarm Output is controlled by the GE864 module and will rise when the alarm starts and fall after the issue of a dedicated AT command This output can be used to power up the GE864 controlling microcontroller or application at the alarm time giving you the possibility to program a timely system wake up to achieve some periodic actions and completely turn off either the application and the GE864 during sleep periods drammatically reducing the sleep comsumption to few pA In battery powered devices this feature will great
62. n authorization of Telit Communications All Right reserved Right of modification reserved page 33 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 The bandwidth 3dB is given by the approximated formula considering C725 gt gt C726 1 _ 1 Hz 2 119 726 2z RT11 C727 The buffer bandwidth at 3dB shall be 8kHz Note that the biasing of the operational amplifier is given for the inverting amplifier by the series divider R714 R715 The 100nF capacitor C719 is needed to filter the noise that could be coupled to that divider For the not inverting operational the biasing is given by a different divider R715 R717 with the capacitor C720 and through a series resistor R718 of 470KQ freq For example Let s assume you have a microphone with these characteristics sensitivity 45 dByrms pa and you want to use it in the external mic audio path With the mic having nominal sensitivity 45dBy mspqaat the normal spoken conditions 4 7dB but at 50 cm from the mouth of the talker an additional 20 dB loss shall be considered At that acoustic pressure the voltage output from the microphone is Mic Voltage Output dB 45 4 7 20 69 7 corresponding to Mic Voltage Output 10 Ese int in order to have a signal of 1 mV 10 dB lower than the nominal input for the GES64 external mic path on the GES64 internal mic in
63. nd this should be kept in mind when designing The internal audio path should be used for handset function while the external audio path is suited for hands free function car kit Both microphone paths from the Telit GE864 are balanced and the OEM circuitry should be designed balanced to reduce the common mode noise typically generated on the ground plane however for particular OEM application needs also an unbalanced circuitry can be used The microphone input lines characteristics are internal microphone path line coupling line type differential input resistance line nominal sensitivity max input voltage microphone nominal sensitivity analog gain suggested echo canceller type external microphone path line coupling line type differential input resistance line nominal sensitivity max input voltage microphone nominal sensitivity analog gain suggested echo canceller type AC 100nF cond balanced 25kQ 50 mV ms 360 MVims 45 dByrms pa 244 handset AC 100nF cond balanced 25kQ 3 22 mMVirms 45 dByrmspa 104 car kit hands free Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 25 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 TIP Due to the difference in the echo canceller type the internal audio path i
64. ophone buffering As seen previously a microphone shall be connected to the input pads of the GE864 through a buffer amplifier that boosts the signal level to the required value Again the buffered microphone circuitry can be balanced or unbalanced Where possible it is always preferable a balanced mic solution The buffering circuit shall be placed close to the microphone or close to the microphone wire connector 6 4 1 Buffered Balanced Mic A sample circuit can be BALANCED MICROPHONE BUFFER 124 dB 39 d 434 R516 S a ATK DECOUPLING CAPACITORS BND UBO2 m 4 159491210 gt E i OSs os LI c B d in L 50 C627 R645 mo Seit 1000F m TO FROM id HEN MIC m li mr n i VID GND SND a 2 m T53VB121D 7 PENE Ox wt E niu Ds cT 4 a eee re a ed ee ee wo FEE LE ia ma TE This circuit has a gain of 15 times 24 dB and is therefore suited for the internal mic input having a microphone with a sensitivity close to the suggested one 45 dByimspa if the used microphone has a different sensitivity or if the buffer is connected to the external mic input then a gain adjustment shall be done by changing resistors R604 R605 and R606 R607 and as a con
65. ption during VOICE CSD transmission rms 270 mA e Average current during Power Saving z 4 mA e Average current during idle Power Saving disabled 9 mA The GSM system is made in a way that the RF transmission is not continuous else it is packed into bursts at a base frequency of about 216 Hz the relative current peaks can be as high as about 2A Therefore the power supply has to be designed in order to withstand with these current peaks without big voltage drops this means that both the electrical design and the board layout must be designed for this current flow If the layout of the PCB is not well designed a strong noise floor is generated on the ground and the supply this will reflect on all the audio paths producing an audible annoying noise at 216 Hz if the voltage drop during the peak current absorption is too much then the device may even shutdown as a consequence of the supply voltage drop TIP The electrical design for the Power supply should be made ensuring it will be capable of a peak current output of at least 2 A 3 2 General Design Rules The principal guidelines for the Power Supply Design embrace three different design steps the electrical design the thermal design the PCB layout Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 9 of 60 Telit GE 864 Telit Hardware User guide Communications S p A
66. puts then the buffer must have a gain of Voltage GE864 intmic Voltage Output 1 10 3 3 10 3 Hence in these conditions the signal level on the input pads of the internal mic of the GE864 is 10 dB 3 times higher than the microphone output and therefore the buffer has to gain 10 dB To calculate the resistor values it must be kept in mind that balancing the line will double the signal and hence already add 6 therefore the buffer must gain only 1 5 times The corresponding values for the resistors on the buffer could be if we keep the input resistance 10kQ R711 gain R708 1 5 10 15 R719 gain 1 R720 1 5 1 10 5 kQ The commercial values of 15kQ amp 5 6kQ are then chosen As a consequence the values of the capacitors C726 and C727 shall be Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 34 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 726 1 2n 8000 R719 3 5 10 727 1 2 8000 8711 1 2 10 The commercial values of 3 3nF and InF are then chosen Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 35 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05
67. rophone on the earpiece cable while the other kind of headset shall be threaten as an handset For example With the external mic having the suggested nominal sensitivity 45dBy mspa at the normal spoken conditions 4 7 at 7 cm from the mouth of the talker and with further attenuation of 20dB due to the distance from the microphone about 50 cm At that acoustic pressure the voltage output from the microphone is Voltage Output dB 45 4 7 20 69 7 corresponding to Voltage Output 10 97 9 3 3 10 Vins by having the microphone gain set to 10 dB corresponding to 3 times the signal in the nominal conditions on the input external mic pads of the GES64 will be Voltage GE864 3 3 10 3 I mV Hence in these conditions the signal level on the input pads of the external mic of the GE864 is 10 dB 3 times lower than the nominal as suggested The microphones usually need a biasing network that provides the necessary DC current to the mic this will be explained further on In the EVK2 all the microphone input jacks have the hot wire connected to the central pole Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 27 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 6 2 General Design Rules There are several config
68. s suited for handset applications while the external audio path is suited for car kit hands free The headset applications should be made by using the external audio path but DISABLING the echo canceller by software AT command If the echo canceller is left active with the headset then some echo might be introduced by the echo cancel algorithm The nominal sensitivity of the line indicates the voltage level on the GE864 pads that should be present during normal spoken conditions for a handset a voice signal coming from the mouth of the talker at 7 cm of distance from the microphone producing an acoustic pressure of 4 7 dBp 1 kHz on the microphone membrane For example With the internal mic having the suggested nominal sensitivity 45dByrms pa at the normal spoken conditions 4 7dB p on the microphone membrane At that acoustic pressure the voltage output from the microphone is Voltage Output dB 45 4 7 49 7 corresponding to Voltage Output 10 7097 3 3 107 p by having the microphone gain set to 24 dB corresponding to 15 8 times the signal in the nominal conditions on the input mic pads of the 864 will be Voltage GE864 3 3 10 15 8 51 MV ims During the spoken conditions the signal varies according to the volume of the voice of the talker usually a rough thumb rule for the dynamic range may be considered 20dB 10 times at maximum voice level talker scre
69. sequence the capacitors C636 and C637 to maintain the bandwidth 150 8000 3dB The buffer gain is given by the formula R604 R606 Gain R605 R607 The C636 and C637 capacitors are placed in order to cut off the gain at higher frequencies than the transmitted GSM band the cutoff frequency 3dB should be 8 kHz in order to have 1dB at 4kHz Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 31 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 The cutoff frequency is given by the formula 1 _ 1 2 604 637 27 R606 C636 freq Hz For example Let s assume you have a microphone with these characteristics sensitivity 45 dByrms pa and you want to use it in the internal mic audio path With the mic having nominal sensitivity 45 at the normal spoken conditions 4 7dB at 7 cm from the mouth of the talker At that acoustic pressure the voltage output from the microphone is Mic Voltage Output dB 45 4 7 49 7 corresponding to Mic Voltage Output 10 77 9 3 3 10 3 Vims in order to have a signal of 50 MV ms the GE864 internal mic inputs then the buffer must have a gain of Voltage 864 intmic Mic Voltage Output 50 10 3 3 10 15 Hence in these conditions the signal
70. t ic mts alt e SIMVCC lt 36 35 MIC_HF Jic N e SIMIN MT 2 MIC MT 8 7 l e 38 49B SIMIN 37 GND O e C201 C202 C203 C204 e 39 33pF 33pF 33pF 33pF 38 GND OF F3 coe cog e GND 40 6 50 50 50 50 39 SND OF OND 0402 0402 0402 0402 GND GND a 77 EB GND GND GND GND m 5 at 23 5 aS Ae Zag lt Tu i e EZ sm z RESET BUTTON Donor R201 SW201 MODIFY 330 5 2 5 gt RESET f 1 DATE 0603 4 SKHHAL 2 1 9B 9C 8 DESCRIPTION a YELLOW STAT LED M676 ON BUTTON PATH home users area YELLOW a NO Ld LY M676 Q281 26 85 FILE 51139 DAI TELECOM EVK 2 DL201 Dai Telecom Group 7 Mod 067 1 11 02 ANNOTATION FORM PROJECT Furlan M 080705 INTERFACE CONNECTORS A 3 L lt STAT LED 9c Serdi M PROJECT SHEET N OF SHEETS DRAWING CODE DRAWN 080705
71. t GE864 Telit Hardware User guide Communications S p A 1vv0300694 Rev ISSUE 2 19 12 05 Annex A EVK2 schematics Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 51 of 60 1 2 4 5 6 7 8 9 10 11 E PL106 9019915102410 PL103 885 1984617PT1 5_2 3 5 H x 889 ee 222 5 alee CURRENT UNLIMITED pa T al ne SI z 2 105 1 BATTERY CHARGER INPUT R105 4 s 4 5 5 CHARGER 1 680 7 sov 6 A 0603 s ES IPES 5 R11
72. t in the full product design and they strongly reflect on the product overall performances hence read carefully and follow the requirements and the guidelines for a proper design 4 1 Antenna Requirements As suggested on the Product Description the antenna and antenna line on PCB for a Telit GE864 device shall fulfil the following requirements ANTENNA REQUIREMENTS Frequency range Standard Dual Band GSM DCS frequency range or Standard Tri Band GSM DCS PCS frequency range if used for all three bands Bandwidth 80 MHz in GSM amp 170 MHz in DCS amp 140 MHz PCS band Gain Gain lt 3dBi Impedance 50 ohm Input power gt 2 W peak power VSWR absolute lt 10 1 max VSWR lt 2 1 recommended When using the Telit GE864 since there s no antenna connector on the module the antenna must be connected to the GE864 through the PCB with the antenna pad In the case that the antenna is not directly developed on the same PCB hence directly connected at the antenna pad of the GE864 then a PCB line is needed in order to connect with it or with its connector Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 16 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 This line of transmission shall fulfil the following requirements ANTENNA LINE ON PCB REQ
73. tion of Telit Communications All Right reserved Right of modification reserved page 18 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 5 Serial Port The serial port on the Telit GE864 is the core of the interface between the module and OEM hardware Several configurations can be designed for the serial port on the OEM hardware but the most common are RS232 PC com port microcontroller UART 2 8V 3V Universal Asynchronous Receive Transmit microcontroller VART 5V or other voltages different from 2 8V Depending from the type of serial port on the OEM hardware a level translator circuit may be needed to make the system work The only configuration that doesn t need a level translation is the 2 8V UART The serial port on the GE864 is a 2 8V UART with all the 7 RS232 signals It differs from the PC RS232 in the signal polarity RS232 is reversed and levels The levels for the GE864 UART are the CMOS levels Absolute Maximum Ratings Not Functional Input level 0 3V 3 75 digital pad when Input voltage on 0 3V 3 0 V analog pads when on Operating Range Interface levels 2 8V CMOS Output low level Vor ov Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 19 of 60 Telit GE864 Telit Hardware User guide Comm
74. unications S p A 1 0300694 Rev ISSUE 2 19 12 05 The signals of the GE864 serial port are RS232 i GE864 Pad Pin Number Number DCD 42 Data Carrier Detect Output from the GE864 that indicates the carrier presence RXD Transmit line see Note Output transmit line of GE864 UART 3 TXD 3T Receive line see Note Input receive of the GE864 UART rx uart 4 39 Data Terminal Ready Input to the GE864 that controls the DTE dtr uart READY condition 5 GND 8 17 28 36 Ground ground 45 48 50 56 DSR 43 Data Set Ready Output from the GE864 that indicates the dsr_uart module is ready 7 RTS 40 Request to Send Input to the GE864 that controls the rts_uart Hardware flow control CTS 41 Clear to Send Output from the GE864 that controls the cts_uart Hardware flow control RI 44 Ring Indicator Output from the GE864 that indicates the ri_uart incoming call condition NOTE According to V 24 RX TX signal names are referred to the application side therefore on the GE864 side these signal are on the opposite direction on the application side will be connected to the receive line here named TXD rx uart of the GE864 serial port and viceversa for RX TIP For a minimum implementation only the TXD and RXD lines can be connected the other lines can be left open provided a software flow control is implemented The signals in the UART connector on the EVK2 are DCD RXD TX
75. urations for the audio path but the most effective difference is between balanced and unbalanced microphone It is highly recommended to keep the whole microphone path balanced even if this means having 2 wires connecting the microphone instead of one needed plus ground in the unbalanced case The balanced circuitry is more suited because of its good common mode noise rejection reducing the 216 Hz burst noise produced during the GSM transmissions e Where possible use balanced microphone circuitry e Keep the microphone traces on the PCB and wires as short as possible e If your application requires an unbalanced microphone then keep the lines on the PCB balanced and unbalance the path close to the microphone wire connector if possible e For the microphone biasing voltage use a dedicated voltage regulator and a capacitor multiply circuit e Make sure that the microphone traces in the PCB don t cross or run parallel to noisy traces especially the power line e If possible put all around to the microphone lines a ground trace connected to the ground plane by several vias This is done in order to simulate a shielded trace on the PCB e The biasing circuit and eventually the buffer can be designed in the same manner for the internal and external microphones 6 3 Microphone Biasing The electret microphones usually need a biasing voltage to work properly Refer to your microphone provider for the characteristics required NOTE T
76. ximize Li lon battery performances and do not need to be changed NOTE In this application the battery charger input current must be limited to less than 400mA This can be done by using a current limited wall adapter as the power source Reproduction forbidden without written authorization of Telit Communications All Right reserved Right of modification reserved page 13 of 60 Telit GE864 Telit Hardware User guide Communications S p A 1 0300694 Rev ISSUE 2 19 12 05 3 2 2Thermal Design Guidelines The thermal design for the power supply heat sink should be done with the following specifications e Average current consumption during transmission PWR level max rms 500mA e Average current consumption during transmission PWR level min rms 100 e Average current during Power Saving 4mA e Average current during idle Power Saving disabled 19mA NOTE The average consumption during transmissions depends on the power level at which the device is requested to transmit by the network The average current consumption hence varies significantly TIP The thermal design for the Power supply should be made keeping a average consumption at the max transmitting level during calls of 500mA rms Considering the very low current during idle especially if Power Saving function is enabled it is possible to consider from the thermal point of view that the device absorbs current significantly only

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