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Fujitsu MB3887 User's Manual

1. Error amplifier gain and phase vs Frequency T Ta 25 C 40 180 VCC 19V Av d T 42V 9 77 240kQ 20 90 _ 10 T gt 10ka 2 D 1 WE 2 0 0 c IN 2 4 KQ S _20 90 ou 3 Error Amp1 10 10 Error Amp2 40 180 777 777 10k 100k 1M 10M Frequency f Hz Error amplifier gain and phase vs Frequency T Ta 25 C L 40 m 180 spe RETI Av Ki 240k 10 Q 20 90 _ 10 AN 5 8 E 2 5 OH 4 z 0 0 IN 2 4 kQ o OUT 20 90 1 Error Amp3 10k0Z 10k03 40 180 77 TT 1k 10k 100 k 1M 10M Frequency f Hz Current detection amplifier gain and phase vs Frequency Ta 25 C 40 180 VCC 19 V A 20 90 gt OUT D 5 1 7 Current Ampi 2 0 0 Current Amp2 c 8 126VT 7 1255V 20 90 777 T 40 180 1k 10k 100 k 1M 10M Frequency f Hz Continued 14 MB3887 Continued Power dissipation vs Ambient temperature 800 740 700 600 500 Power dissipation Po mW 40 20 0 20 40 60 80 100 Ambient
2. am vo i ani 2200 49 T 6255 Sse 10 ZI S euw ALNO OY OEE paijdde aBeyon yeu mont os 1ndino 19S 0091 JON 002 T J3HA 81H aiqeysnipe si eBeyoa TTT p QE Blu a PR zen LI 1ndino ANN ls dd 0 m E Old 1 lt HA gt Il i b 25 por A 9 99A I HA seig ia ZE 2 1 JOA 338A 1 00 Hl zz lt zdwy 1043 00 9 PRE cere ee lue OA HH LI LO H A y gt d bl Quz Li 22 a etti n gt 99 oidepv ov EET gt Nil O 99 O N E 189 p 1e J3HA ASCOIAS97L 7 NIA duy 10413 019 CO eo SZ 0 NIA DI 001 8 to lt B 24 MB3887 PARTS LIST COMPONENT Diode SPECIFICATION VDS 30 V ID 8 A Max VDS 60 V ID 0 115 A Max VF 0 42 V Max IF 3 A VENDOR VISHAY SILICONIX VISHAY SILICONIX ROHM PARTS No Si4435DY 2N7002bE RBO053L 30 Inductor 3 5 A 31 6 22 uH mo TDK SLF12565T 220M3R5 OS CON Electrolytic Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Ceramics Condenser Cer
3. MB3887 EE FUJITSU LIMITED All Rights Reserved The contents of this document are subject to change without notice Customers are advised to consult with FUJITSU sales representatives before ordering The information and circuit diagrams in this document are presented as examples of semiconductor device applications and are not intended to be incorporated in devices for actual use Also FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use of this information or circuit diagrams The products described in this document are designed developed and manufactured as contemplated for general use including without limitation ordinary industrial use general office use personal use and household use but are not designed developed and manufactured as contemplated 1 for use accompanying fatal risks or dangers that unless extremely high safety is secured could have a serious effect to the public and could lead directly to death personal injury severe physical damage or other loss i e nuclear reaction control in nuclear facility aircraft flight control air traffic control mass transport control medical life support system missile launch control in weapon system or 2 for use requiring extremely high reliability i e submersible repeater and artificial satellite Please note that Fujitsu will not be liable against you and or any thir
4. Continued MB3887 Continued Soft start operating waveform Discharge operating waveform constant voltage mode constant voltage mode set at 12 6 V set at 12 6 V VBATT V VBATT V 20 4 20 Ta 25 C VIN 19 V LI 10 TF BATT 129 10 4 Or 0 Vcs V Vcs V 4 4 4 4 2 24 0 o Ta 25 4 VOTE AN Vert V Vor VIN 19 V 5 f BATT 120 0 r T T T T T T T T 1 0 T 1 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 ms ms Soft start operating waveform Discharge operating waveform constant voltage mode constant voltage mode set at 16 8 V set at 16 8 V VBarr V VBATT V 20 4 20 4 VIN 19 V 10 4 0 Vcs V 4 4 2 ge ver M von 5 5 TITTI i BATT 12 0 0 0 2 4 6 8 10 12 14 16 18 20 ms 0 2 4 6 8 10 12 14 16 18 2 ms 29 30 MB3887 USAGE PRECAUTIONS Printed circuit board ground lines should be set up with consideration for common impedance Take appropriate static electricity measures Containers for semiconductor materials should have anti static protection or be made of conductive material e After mounting printed circuit boards should be s
5. 84 Efficiency n 8 82 VBATT IBATT 5 82 VBATT IBATT VIN x liN x 100 VIN x lin x 100 80 111111 1 LI oe 80 1 1 1 1 1 1 1 1 10m 100 m 1 10 0 2 4 6 8 10 12 14 16 18 20 BATT charge current leatr A BATT charge voltage Vaarr V Continued MB3887 _ Conversion efficiency vs Charge current Conversion efficiency vs Charge current Constant voltage mode Constant current mode 100 100 amp 98 5 98 96 96 3 5 2 94 94 5 92 5 9 2 Ta 25 C 2 25 9 VIN 19 V 90 VIN 19V 5 88 BATT charge voltage 5 88 BATT charge voltage 86 set at 16 8 V Ez 86 set at 16 8 V o SW ON SW ON 84 Efficiency n 36 84 Efficiency n 4 8 82 VBATT IBATT 8 82 VBATT IBATT J I VIN x lin x 100 VIN x lin x 100 80 MARNE 1 L iiil 80 1 1 1 1 1 1 1 1 10 100m 1 10 0 2 4 6 8 10 12 14 16 18 20 BATT charge current leatr A BATT charge voltage Vaarr V BATT voltage vs BATT charge current BATT voltage vs BATT charge current set at 12 6 V set at 16 8 V 18 T 20 T T T EE T T Ta 25 C VIN 19V BA
6. FUJITSU SEMICONDUCTOR DATA SHEET DS04 27709 3E ASSP For Power Supply Applications Secondary battery DC DC Converter IC for Charging Li ion battery MB3887 DESCRIPTION The MB3887 is a DC DC converter IC suitable for down conversion using pulse width PWM charging and enabling output voltage to be set to any desired level from one cell to four cells These ICs can dynamically control the secondary battery s charge current by detecting a voltage drop in an AC adapter in order to keep its power constant dynamically controlled charging The charging method enables quick charging for example with the AC adapter during operation of a notebook PC The MB3887 provides a broad power supply voltage range and low standby current as well as high efficiency making it ideal for use as a built in charging device in products such as notebook PC This product is covered by US Patent Number 6 147 477 B FEATURES Detecting a voltage drop in the AC adapter and dynamically controlling the charge current Dynamically controlled charging Continued PACKAGE 24 pin plastic SSOP FPT 24P M03 cO FUJITSU MB3887 eee Continued Output voltage setting using external resistor 1 cell to 4 cells High efficiency 9696 VIN 19 V Vo 16 8 V Wide range of operating supply voltages 8 25 V Output voltage setting accuracy 4 2V 0 7496 Ta 2 10 C to 85 C per cell
7. 400 4 E 300 5 5 i 200 2 2 O 100 1 o 0 0 0 5 10 15 20 25 CTL terminal voltage Vcr V Continued 12 MB3887 Triangular wave oscillation frequency Triangular wave oscillation frequency vs Timing resistor vs Power supply voltage 1 M I I EE 340 25 VCC 19V 5 330 Su CTL 5V 5 qi 40 De DD 9 8 A 310 8 S gt 100k gt 42 300 2 5 Ce 290 DI D D 5 280 c 5 1877 270 10k 260 10 100 1000 0 5 10 15 20 25 Timing resistor Rr kQ Power supply voltage Vcc V Triangular wave oscillation frequency Error amplifier threshold voltage vs Ambient temperature vs Ambient temperature 320 4 25 315 VCC 19V 2 24 c 310 D CTL 5V 4 23 Ta 305 3 N 0 lt 222 L 300 5 D 295 421 O o CE 8 290 gt 420 BS 285 EN Q 280 ES ads S S 275 4 D 8 270 4 17 amp 265 ui 4 16 E 260 4 15 40 20 0 20 40 60 80 100 40 20 0 20 40 60 80 100 Ambient temperature Ta C Ambient temperature Ta C Continued 13 MB3887
8. Battery charging voltage Vo Vo V R3 R4 R4 x 4 2 V Vo R3 lt Error Amp3 gt R4 OUTD H 1 ncn METHOD OF SETTING THE CHARGING CURRENT The charge current output limit current value can be set with the voltage at the INE1 terminal pin 9 If a current exceeding the set value attempts to flow the charge voltage drops according to the set current value Battery charge current setting voltage INE1 INE1 V 20 1 A x Rs METHOD OF SETTING THE TRIANGULAR WAVE OSCILLATION FREQUENCY The triangular wave oscillation frequency can be set by the timing resistor Rr connected the RT terminal pin 17 Triangular wave oscillation frequency fosc fosc KHz 13630 Rr i METHOD OF SETTING THE SOFT START TIME For preventing rush current upon activation of IC the IC allows soft start using the capacitor Cs connected to the CS terminal pin 22 MB3887 When CTL terminal pin 14 is placed under level and IC is activated Vcc gt UVLO threshold voltage Q2 is turned off and the external soft start capacitor Cs connected to the CS terminal is charged at 10 uA Error Amp output FB3 terminal pin 15 is determined by comparison between the lower voltage of the two non reverse input terminals 4 2 V and CS terminal voltage and reverse input terminal voltage terminal pin 16 voltage Within the soft
9. t 1 fosc x Duty Peak output current Power dissipation Ta lt 25 C Storage temperature The package is mounted on the dual sided epoxy board 10 cm x 10 cm WARNING Semiconductor devices can be permanently damaged by application of stress voltage current temperature etc in excess of absolute maximum ratings Do not exceed these ratings RECOMMENDED OPERATING CONDITIONS Parameter Power supply voltage Conditions VCC VCC O terminal MB3887 Reference voltage output current VH terminal output current Input voltage to INE3 INE1 INE2 terminal INC1 INC2 INC1 2 terminal OUTD terminal output voltage OUTD terminal output current CTL terminal input voltage Output current Peak output current Oscillation frequency Duty x 5 t 1 fosc x Duty Timing resistor Soft start capacitor VH terminal capacitor Reference voltage output capacitor Operating ambient temperature WARNING The recommended operating conditions are required in order to ensure the normal operation of the semiconductor device All of the device s electrical characteristics are warranted when the device is operated within these ranges Always use semiconductor devices within their recommended operating condition ranges Operation outside these ranges may adversely affect reliability and coul
10. Standard design value Isink FB1 FB2 2V Continued Parameter 5 2 Error amplifier block Error Amp3 6 Current detec tion amplifier block Current Threshold voltage MB3887 Ta 25 C 19 V VCC 19 V VREF 0 mA Conditions FB3 2 V Ta 25 C 2 V Ta 10 to 85 C Input current INE3 0 V Voltage gain DC Frequency bandwidth Output voltage VFBH VeeL Output source current source FB3 2V Output sink current Isink FB3 2V OUTD terminal output leak current ILEAK OUTD 17 V OUTD terminal output ON resistor Input offset voltage Ron OUTD 1 mA INC1 INC2 INC1 INC2 3 V to VCC Ampi Current Input current Amp2 Standard design value INC1 INC2 3 V to VCC 100 mV INC1 INC2 3 V to VCC AVin 100 mV INC1 INC2 0 AVin 100 mV iNcL INC1 INC2 0 V AVin 100 mV Continued MB3887 E Ta 425 C VCC 19 V VCC 19 V VREF 0 mA i Value Parameter y si No Conditions Unit o 0 INC1 INC2 2 10 3 V to VCC 1 9 2 0 2 1 V AVin 100 mV INC1 INC2 Vourc2 2 10 3 V to VCC 0 34 0 40 0 46 V Current dete
11. VH VCC VCC Output voltage 8Vto25V Vcc 6 5 Vcc 5 5 VH 0 to 30 mA VCC VCC 0 CTL 0V Power supply cur VCC VCC rent CTL 5V Standby current Standard design value 11 MB3887 TYPICAL CHARACTERISTICS Power supply current vs Power supply voltage Reference voltage vs Power supply voltage 6 T T 6 Ta 25 C 5 CTL 5V 4 Ta 25 C CTL 5V VREF 2 0 mA 0 10 15 20 25 0 10 15 20 25 Power supply current lcc mA wo Reference voltage Vrer V Power supply voltage Vcc V Power supply voltage Vcc V Reference voltage vs load current Reference voltage vs Ambient temperature 5 08 VCC 19V 5 06 CTL 5V 1 5 04 25 C VCC 19V CTL 5V 5 02 5 00 Eque 4 98 4 96 4 94 Reference voltage Vreer V wo Reference voltage Vrer V 0 4 92 5 10 15 20 25 30 40 20 0 20 40 60 80 100 Irer load current Ingr MA Ambient temperature Ta CTL terminal current Reference voltage vs CTL terminal voltage x 1000 T T T 10 3 Ta 25 C A 900 19 gt 5 800 8 m 5 700 7 e 600 6 5 VREF fo 500 5 5 o gt
12. temperature Ta C 15 MB3887 FUNCTIONAL DESCRIPTION 1 DC DC Converter Unit 1 Reference voltage block Ref The reference voltage generator uses the voltage supplied from the VCC terminal pin 18 to generate a tem perature compensated stable voltage 5 0 V Typ used as the reference supply voltage for the IC s internal circuitry This terminal can also be used to obtain a load current to a maximum of 1mA from the reference voltage VREF terminal pin 6 2 Triangular wave oscillator block OSC The triangular wave oscillator builds the capacitor for frequency setting into and generates the triangular wave oscillation waveform by connecting the frequency setting resistor with the RT terminal pin 17 The triangular wave is input to the PWM comparator on the IC 3 Error amplifier block Error Amp1 This amplifier detects the output signal from the current detection amplifier Current amp1 compares this to the INE1 terminal pin 9 and outputs a PWM control signal to be used in controlling the charging current In addition an arbitrary loop gain can be set up by connecting a feedback resistor and capacitor between the FB1 terminal pin 7 and INE1 terminal pin 8 providing stable phase compensation to the system 4 Error amplifier block Error Amp2 This amplifier Error Amp2 detects voltage drop of the AC adapter and outputs a PWM control signal In addition an arbitrary loop gain can be se
13. Charging current accuracy 5 Built in frequency setting capacitor enables frequency setting using external resistor only Oscillation frequency range 100 kHz to 500 kHz Built in current detection amplifier with wide in phase input voltage range 0 V to VCC In standby mode leave output voltage setting resistor open to prevent inefficient current loss Built in standby current function 0 uA standard Built in soft start function independent of loads Built in totem pole output stage supporting P channel MOS FET devices PIN ASSIGNMENT MB3887 INC2 OUTC2 INE2 INE2 NE1 INE1 OUTC1 OUTD VIEW FPT 24P M03 INC2 GND CS VCC O OUT VH VOC RT INES CTL INC1 MB3887 PIN DESCRIPTION Current detection amplifier Current Amp2 input terminal Current detection amplifier Current Amp2 output terminal Error amplifier Error Amp2 non inverted input terminal Error amplifier Error Amp2 inverted input terminal Error amplifier Error Amp2 output terminal Reference voltage output terminal Error amplifier Error Amp1 output terminal Error amplifier Error Amp1 inverted input terminal AJ Ww D Error amplifier Error Amp1 non inverted input terminal Current detection amplifier Current Amp1 output termin
14. NCE DATA Conversion efficiency vs Charge current Constant voltage mode 100 98 96 94 Ta 25 C VIN 19V BATT charge voltage set at 12 6 V SW ON 100 98 96 94 Conversion efficiency vs Charge current Constant current mode 25 C VIN 19 V BATT charge voltage setat 12 6V SW ON 26 S ps gt a 92 Efficiency n 8 92 Efficiency n 90 VBATT x IBATT 90 L VBATTXIBATT VIN x liN x 100 v VIN x liN E 59 5 887 x 100 52 86 D 86 84 gt 84 c 8 8 8 82 80 80 10m 100 m 1 10 0 2 4 6 8 10 12 14 16 BATT charge current leatr A BATT charge voltage Vesar V Conversion efficiency vs Charge current Conversion efficiency vs Charge current Constant voltage mode Constant current mode 100 100 amp 98 amp 98 96 96 94 e 94 8 92 2 92 E Ta 25 25 VIN 19 V o 90 VIN 19 V 5 88 BATT charge voltage 88 BATT charge voltage 9 go set at 16 8 V D 86 set at 16 8 V SW ON o SW ON 84 Efficiency n 96
15. TT Electronic load 16 BATT Electronic load 18 Product of KIKUSUI PLZ 150W 7 c 14 Product of KIKUSUI PLZ 150W lt S 16 Ta 25 C 4 de 14 VIN 19V amp 12 lt 12 gt 40 gt Dead Battery MODE DCG MODE 10 Dead Battery MODE DCC MODE 58 5 6 5 6 H H 4 4 lt lt 2 m 2 DCC Dynamically Controlled DCC Dynamically Controlled 0 05 1 15 2 25 3 35 4 45 5 0 05 1 15 2 25 3 35 4 45 5 BATT charge current leatr BATT charge current leatt A Continued 27 28 MB3887 Switching waveform constant voltage mode set at 12 6 V Ta 25 VIN 19V 1 5 VBATT mV 100 0 100 Vo V 1 0 1 2 3 4 5 6 7 8 9 10 us Switching waveform constant voltage mode set at 16 8 V VBATT mV TN 5 100 FBATT 1 5 0 100 Vb V Switching waveform constant current mode set at 12 6 V with 10 V VBarr mV 100 0 100 VD V 0 1 2 3 4 5 6 7 8 9 10 us Switching waveform constant current mode set at 16 8 V with 10 V Ta 25 C VBATT MV 19 v 100 BATT 3 0 A tog mVp p 0 VD 100 Vo V 0 12 3 4 5 6 7 8 9 10 us
16. al With IC in standby mode this terminal is set to Hi Z to prevent loss of current through output voltage setting resistance Set CTL terminal to H level to output L level Current detection amplifier Current Amp1 input terminal Current detection amplifier Current Amp1 input terminal Power supply control terminal Setting the CTL terminal at L level places the IC in the standby mode Error amplifier Error Amp3 output terminal Error amplifier Error Amp3 inverted input terminal Triangular wave oscillation frequency setting resistor connection terminal Power supply terminal for reference power supply and control circuit Power supply terminal for FET drive circuit VH 6 V External FET gate drive terminal Output circuit power supply terminal Soft start capacitor connection terminal Ground terminal Current detection amplifier Current Amp2 input terminal BLOCK DIAGRAM MB3887 Error Amp1 gt VREF 1 lt PWM Comp gt lt Error Amp2 gt VREF AN 2 5 VV 1 5 V lt Error Amp3 gt lt UVLO gt VREF lt OSC gt 45 pF L dco MB3887 SSS SSS ss x ABSOLUTE MAXIMUM RATINGS Parameter Conditions Power supply voltage VCC VCC O terminal Output current Duty lt 5
17. amics Condenser 22 uF 100 uF 0 022 uF 0 1 uF 1500 pF 0 1 uF 10000 pF 0 1 uF 5600 pF 25 V 10 25 V 10 50 V 16 V 10 V 25V 10 V 16 V 10 V SANYO SANYO TDK KYOCERA MURATA MURATA MURATA KYOCERA MURATA 25SL22M 25CV100AX C1608JB1H223K CM21W5R104K16 GRM39B152K10 GRM39F104KZ25 GRM39B103K10 CM21W5R104K16 GRM39B562K10 R10 to R12 R13 R14 R15 R16 R18 R17 R19 Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor 0 033 Q 47 330 kQ 82 330 kQ 68 kQ 22 kQ 100 kQ 10 30 20 1 ko 120 0 200 kQ 100 1 0 96 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 0 0 5 0 5 0 5 0 5 0 5 0 5 Note VISHAY SILICONIX VISHAY Intertechnology Inc ROHM ROHM CO LTD TDK TDK Corporation SANYO SANYO Electric Co Ltd KYOCERA Kyocera Corporation MURATA Murata Manufacturing Co Ltd SEIDEN TECHNO SEIDEN TECHNO CO LTD KOA KOA Corporation ssm SUSUMU Co Ltd OS CON is a trademark of SANYO Electric Co Ltd SEIDEN TECHNO KOA KOA KOA KOA KOA KOA KOA KYOCERA KOA KOA KOA ssm KOA KOA RK73Z1J 0D RK73G1J 473D RK73G1J 334D RK73G1J 823D RK73G1J 334D RK73G1J 683D RK73G1J 223D RK73G1J 104D CR21 103 F RK73G1J 303D RK73G1J 203D RK73G1J 102D RR0816P121D RK73G1J 204D RK73G1J 104D 25 MB3887 M REFERE
18. ction AVin 20 mV voltage INC1 INC2 Vourcz 2 10 0 V to 3 V 1 8 2 0 2 2 V AVin 100 mV INC1 INC2 Voutca 2 10 0 V to 3 V 0 2 0 4 0 6 V 6 AVin 20 mV Current ds detection In phase input 12 amplifier block voltage range Vom 13 0 Vcc V Current Ampli 24 Current Amp2 4INC2 Voltage gain 2 10 3Vto VCC 19 20 21 VN AVin 100 mV Frequency bandwidth BW 2 10 AV 0 dB 2 MHz Vourcx 2 10 4 7 4 9 V Output voltage 2 10 20 200 mV OUTCISOUTCA 2V 2 1 mA current 2 sinkcur 2 10 OUTC1 OUTC2 2V 150 300 pA 7 5 7 PWM Vit 15 Duty cycle 0 1 4 1 5 V comparator Threshold voltage block 9 7 V 45 Duty cycle 100 2 5 2 6 V PWM Comp Standard design value Continued MB3887 _ 888888888808585885 Continued Ta 25 C VCC 19 V VCC 19 V VREF 0 mA Parameter Conditions Output source ae OUT 13V Duty x 5 current s t 1 fosc x Duty Output sink ER OUT 19 V Duty lt 5 current t 1 fosc x Duty 8 OUT 45 mA Output block Output ON OUT resistor OUT 45 mA OUT 3300 pF Si4435 x 1 OUT 3300 pF Si4435 x 1 IC Active mode IC Standby mode Rise time Fall time 9 CTL input voltage Control block CTL CTL 5V Input current CTL 0V 10 Bias voltage block
19. d party for any claims or damages arising in connection with above mentioned uses of the products Any semiconductor devices have an inherent chance of failure You must protect against injury damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy fire protection and prevention of over current levels and other abnormal operating conditions If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign Exchange and Foreign Trade Law of Japan the prior authorization by Japanese government will be required for export of those products from Japan F0211 FUJITSU LIMITED Printed in Japan
20. d result in device failure No warranty is made with respect to uses operating conditions or combinations not represented on the data sheet Users considering application outside the listed conditions are advised to contact their FUJITSU representatives beforehand MB3887 eee ELECTRICAL CHARACTERISTICS Ta 25 C 19 V VCC 19 V VREF 0 mA Parameter 1 Reference voltage block REF Output voltage Conditions Ta 25 C Ta 10 C to 85 C Input stability VCC 8 V to 25 V Load stability VREF 0 mA to 1 mA Short circuit output current VREF 1V 2 Under voltage lockout protec tion circuit block UVLO Threshold voltage VCC VCC VCC F VCC VCC VCC Hysteresis width VCC VCC O Threshold voltage VREF VREF Y Hysteresis width 3 Soft start block SOFT 4 Triangular waveform os cillator circuit block OSC Charge current Oscillation frequency fosc RT 247 Frequency temperature stability Af fdt Ta 30 to 85 C 5 1 Error amplifier block Error Amp1 Error Amp2 Input offset voltage FB1 FB2 2V Input bias current In phase input voltage range Voltage gain Frequency bandwidth BW Output voltage VraH VraL Output source current IsouRcE FB1 FB2 2V Output sink current
21. ging 20 MB3887 _ 88888888888805855885 PROCESSING WITHOUT USING THE CURRENT When Current Amp is not used connect the INC1 terminal pin 13 INC2 terminal pin 24 INC1 terminal pin 12 and INC2 terminal pin 1 to VREF and then leave OUTC1 terminal pin 10 and OUTC2 terminal pin 2 open Open Connection when Current Amp is not used 21 MB3887 SSS PROCESSING WITHOUT USING OF THE ERROR AMP When Error Amp is not used leave FB1 terminal pin 7 FB2 terminal pin 5 open and connect the INE1 terminal pin 8 and INE2 terminal 4 to GND and connect INE1 terminal pin 9 and INE2 terminal pin 3 to VREF Open Connection when Error Amp is not used 22 MB3887 _ 88888888888805855885 PROCESSING WITHOUT USING OF THE CS TERMINAL When soft start function is not used leave the CS terminal pin 22 open Open cs 2 O Connection when soft start time is not specified NOTE AN EXTERNAL REVERSE CURRENT PREVENTIVE DIODE Insert a reverse current preventive diode at one of the three locations marked to prevent reverse current from the battery When selecting the reverse current prevention diode be sure to consider the reverse voltage Vn and reverse current In of the diode Battery 3 23
22. hen the power supply VCC is turned on may cause malfunctions in the control IC resulting in breakdown or degradation of the system To prevent such malfunction the under voltage lockout protection circuit detects a supply voltage or internal reference voltage drop and fixes the OUT terminal pin 20 to the H level The system restores voltage supply when the supply voltage or internal reference voltage reaches the threshold voltage of the under voltage lockout protection circuit Protection circuit UVLO operation function table When UVLO is operating VCC or VREF voltage is lower than UVLO threshold voltage Spie EMEN GNE NNNM NNNM MB3887 eee 3 Soft Start Function Soft start block SOFT Connecting a capacitor to the CS terminal pin 22 prevents rush currents when the IC is turned on Using an error amplifier for soft start detection makes the soft start time constant being independent of the output load of the DC DC converter SETTING THE CHARGING VOLTAGE The charging voltage DC DC output voltage can be set by connecting external voltage setting resistors R3 R4 to the terminal pin 16 Be sure to select a resistor value that allows you to ignore the on resistor 85 Q 1mA of the internal FET connected to the OUTD terminal pin 11 In standby mode the charging voltage is applied to OUTD termial Therefore output voltage must be adjusted so that voltage applied to OUTD terminal is 17 V or less
23. r circuit is a voltage pulse width converter for controlling the output duty of the error amplifiers Error Amp1 to Error Amp3 depending on their output voltage The PWM comparator circuit compares the triangular wave generated by the triangular wave oscillator to the error amplifier output voltage and turns on the external output transistor during the interval in which the triangular wave voltage is lower than the error amplifier output voltage 8 Output block OUT The output circuit uses a totem pole configuration capable of driving an external P channel MOS FET The output L level sets the output amplitude to 6 V Typ using the voltage generated by the bias voltage block VH This results in increasing conversion efficiency and suppressing the withstand voltage of the connected external transistor in a wide range of input voltages 9 Control block CTL Setting the CTL terminal pin 14 low places the IC in the standby mode The supply currentis 10 LA at maximum in the standby mode CTL function table OFF Standby ON Active 10 Bias voltage block VH The bias voltage circuit outputs Vcc 6 V Typ as the minimum potential of the output circuit In the standby mode this circuit outputs the potential equal to VCC 2 Protection Functions Under voltage lockout protection circuit UVLO The transient state or a momentary decrease in supply voltage or internal reference voltage VREF which occurs w
24. start period CS terminal voltage 4 2 V FB3 is determined by comparison between terminal voltage and CS terminal voltage and DC DC converter output voltage goes up propor tionately with the increase of CS terminal voltage caused by charging on the soft start capacitor Soft start time is found by the following formula Soft start time ts time to output 100 ts s 0 42 x Cs uF CS terminal voltage 4 2 nes SS Sa a Comparison with Error Amp block E INE3 0V Soft start time ts voltage Cs AH VREF t t 10 uA 10 uA 777 FB3 15 Error INE3 16 abs cs CI 42V rl 777 Soft start circuit 19 MB3887 eee AC ADAPTOR VOLTAGE DETECTION With an external resistor connected to the INE2 terminal pin 3 the IC enters the dynamically controlled charging mode to reduce the charge current to keep AC adapter power constant when the partial potential point A of the AC adapter voltage VCC becomes lower than the voltage at the INE2 terminal AC adapter detection voltage setting Vth Vth V R1 R2 R2x INE2 Error Amp2 gt 2 OO 77 A VCC W R1 2 R2 OPERATION TIMING DIAGRAM Error Amp2 FB2 Error Amp1 FB1 Error Amp2 FB3 OUT gt gt lt AC adapter dynamically Constant voltage control Constant current control controlled char
25. t by connecting a feedback resistor and capacitor from the FB2 terminal pin 5 to the INE2 terminal pin 4 of the error amplifier enabling stable phase compensation to the system 5 Error amplifier block Error Amp3 This error amplifier Error Amp3 detects the output voltage from the DC DC converter and outputs the PWM control signal External output voltage setting resistors can be connected to the error amplifier inverted input terminal to set the desired level of output voltage from 1 cell to 4 cells In addition an arbitrary loop gain can be set by connecting a feedback resistor and capacitor from the FB3 terminal pin 15 to the INE3 terminal pin 16 of the error amplifier enabling stable phase compensation to the system Connecting a soft start capacitor to the CS terminal pin 22 prevents rush currents when the IC is turned on Using an error amplifier for soft start detection makes the soft start time constant independent of the output load 6 Current detection amplifier block Current Amp1 The current detection amplifier Current Amp1 detects a voltage drop which occurs between both ends of the output sense resistor Rs due to the flow of the charge current using the INC1 terminal pin 13 and INC1 terminal pin 12 Then it outputs the signal amplified by 20 times to the error amplifier Error Amp1 at the next stage MB3887 _ 88888888888805855885 7 PWM comparator block PWM Comp The PWM comparato
26. tored and shipped in conductive bags or containers Work platforms tools and instruments should be properly grounded Working personnel should be grounded with resistance of 250 kO to 1 MO between body and ground Do not apply negative voltages e The use of negative voltages below 0 3 V may create parasitic transistors on LSI lines which can cause malfunction ORDERING INFORMATION Partnumber Remake 24 pin plastic SSOP MB3887 _ 88888888888805855885 PACKAGE DIMENSION 24 pin plastic SSOP Note1 Pins width and pins thickness include plating thickness FPT 24P M03 Note2 This dimension does not include resin protrusion 7 75 0 10 305 004 0 17 0 03 007 001 J 5 60 0 10 7 60 0 20 220 004 299 008 INDEX Details of A part 1 25 010 008 049 50 Mounting height T esta i hos Y x 2 6 A f es L 0 65 026 0 08 tree 0 18 005 a 0 10 0 10 s 003 i EU EU 020 008 004 004 0 60 0 15 Stand off 024 006 lt 0 10 004 2001 FUJITSU LIMITED 240185 3 4 Dimensions in mm inches

Fujitsu MB3887 User's Manual

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