AN11186 - NXP Semiconductors
Contents
1. s a eee eee 12 Fig 5 RC network on pin Vpp 20ee eee 13 Fig 6 Tamper detection circuit with two push buttons 13 Fig 7 Application diagram timekeeping 14 Fig 8 Application diagram timekeeping and CLKOUT 15 Fig 9 Application diagram timekeeping CLKOUT and power management 16 Fig 10 Application diagram timekeeping CLKOUT and timestamp ii neira 0 cee eee eee 17 Fig 11 Application diagram timekeeping CLKOUT power management and timestamp 18 Fig 12 Application diagram timekeeping CLKOUT power management timestamp battery connected and supply of an external device 19 Fig 13 Application diagram timekeeping CLKOUT power management timestamp battery connected and supply of a microcontroller 20 AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 24 of 25 NXP Semiconductors AN11186 Application and soldering information for the PCA2129 and PCF2129 11 Contents 5 2 5 2 1 5 3 5 4 5 5 5 6 5 7 5 8 5 9 5 10 Introduction 52 55 26 ee cee he ee ecw ae eee 3 Frequency stability and time accuracy 4 Frequency measurement 5 Reflow soldering 00sec eeeeeeneee 7 Introduction to reflow soldering 7 Reflow soldering of2. AN11186 Application and soldering information for the PCA2129 and PCF2129 TCXO RTC Rev 3 18 December 2014 Application note Document information Info Content Keywords PCA2129 PCF2129 application timekeeping timestamp soldering Abstract This application note gives additional information about soldering and application configuration of the PCA2129 and PCF2129 TCXO RTCs NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 Revision history Rev Date Description v 3 20141218 revised version v 2 20130208 revised version v 1 20120608 new application note initial release Contact information For more information please visit http www nxp com For sales office addresses please send an email to salesaddresses nxp com AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 2 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 1 Introduction AN11186 This application note provides additional information on the PCA2129 and PCF2129 TCXO RTCs The accuracy of time given by an RTC is mostly depending on the accuracy of the crystal used For example a tuning fork crystal resonates at room temperature at its nominal frequency b
3. while the PCA2129 and PCF2129 are heated above Tc 255 C must not exceed 30 s tp otherwise the characteristics of the crystal oscillator is degraded or the device may even be damaged 4 3 Effect of reflow soldering on the frequency characteristics The reflow soldering process is typically generating a negative frequency shift After one time reflow soldering processed in accordance with the recommended temperature profile shown in Figure 3 and Table 3 a frequency shift of 2 ppm is typical Any other reflow temperature profile or multiple soldering may cause a different frequency shift after soldering The frequency shift after soldering can be reduced by lowering the peak temperature Tp and shortening the time tp of the soldering process see Figure 3 and Table 3 4 4 Frequency correction after reflow soldering In order to compensate for a shift in frequency due to reflow soldering a frequency offset can be programmed through bits AO 3 0 of register address 19h In the typical case and under consideration of the temperature profile as given in Figure 3 an offset of 2 ppm is considered to be most suitable However this may vary on a per case basis and in dependence of the actual soldering profile used Remark 1 The typical frequency shift of 2 ppm that occurs after a one time reflow soldering processed in accordance with the recommended temperature profile shown in Figure 3 and Table 3 can be corrected by programming
4. PCA2129 and PCF2129 7 Effect of reflow soldering on the frequency Characteristics 00 2200 eee 9 Frequency correction after reflow soldering 9 Optimization at room temperature 10 Application information 11 Assembly recommendations 11 General application information 11 Current consumption 00 11 Battery switch over applications 12 Timestamp applications 13 Timekeeping applications 14 Timekeeping and CLKOUT 15 Timekeeping CLKOUT and power management 16 Timekeeping CLKOUT and timestamp 17 Timekeeping CLKOUT power management and timestamp 0 eee eee eee eee 18 Timekeeping CLKOUT power management timestamp battery connected and supply of an external device 00 cee ee 19 Abbreviations 000 c cece 20 References wiiiois cies sted eee eee ae 21 Legal information 00e eee eens 22 Definitions 2 0 cee 22 DisclaimMel S seuen Bas wate eke ek Sie tet 22 Trademarks 0 0 cc eee 22 WANDS S58 aise ns eh een Spee wena lain ee ace eee a 23 PIQUIOS wid iia cd ee eee aie apace eee ar 24 Contents soe 5 5a us i Seer cee cae a mate 25 Please be aware that important notices concerning this document and the product s described herein have been included in section Legal information NXP Semiconductors N V 2014 All r
5. although with a single timestamp input pin Two push buttons can be connected to the timestamp input pin Time and date are stored when one of the push buttons is pushed A typical application is an electrical meter where one cover protects the terminal terminal case and another cover protects the electronics electronic case and an opening of each of them should be registered Figure 6 shows the double tamper detection application Voper int R1 200 kQ 20 R2 220 KQ PCx2129 5 push button 2 push button 1 L 1 A connected to E connected to ae TF cover 2 cover 1 adi adi Vss aaa 016131 1 When using switches or push buttons it is recommended to connect a 1 nF capacitance to the TS pin to ensure proper switching Fig 6 Tamper detection circuit with two push buttons All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 13 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 e When cover 1 is opened the push button 1 is closed and the TS pin is driven to the R2 Vpp s RIERA Vop For proper functionality R2 220 KQ with a maximum variation of 5 and a low resistive push button must be used intermediate level V Event 1 TSF1 is set date and time is registere
6. and supply of a microcontroller 6 Abbreviations Table 5 Abbreviations Acronym Description CMOS Complementary Metal Oxide Semiconductor G Inter Integrated Circuit IC Integrated Circuit MCU Microcontroller Unit PCB Printed Circuit Board PPM Parts Per Million RAM Random Access Memory RTC Real Time Clock SMD Surface Mount Device SPI Serial Peripheral Interface SRAM Static Random Access Memory TCXO Temperature Compensated Xtal Oscillator Xtal crystal AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 20 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 7 References 1 AN10365 Surface mount reflow soldering description 2 IEC 61340 5 Protection of electronic devices from electrostatic phenomena B IPC JEDEC J STD 020 Moisture Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices 4 JESD625 A Requirements for Handling Electrostatic Discharge Sensitive ESDS Devices 5 PCA2129 Automotive accurate RTC with integrated quartz crystal Data Sheet 6 PCF2129 Accurate RTC with integrated quartz crystal for industrial applications Data Sheet 7 UM10204 C bus specification and user manual 8 UM10301 Us
7. external device SRAM VDD to the MCU INT PCx2129 J L4 100 nF Batt 100 nF ves LT aaa 005280 Fig 12 Application diagram timekeeping CLKOUT power management timestamp battery connected and supply of an external device For using the PCA2129 and PCF2129 for timekeeping power management CLKOUT with a battery connected and supplying a microcontroller see Figure 13 e CLKOUT is connected to Vpp using a pull up resistor e CLKOUT is enabled at 32 768 kHz by default after start up COF 2 0 000 e A battery is attached to the Vgar pin e The battery switch over and the battery low detection functions are enabled by default PWRMNG 2 0 000 e The timestamp detection is enabled by default TSOFF 0 e BBS supplies a microcontroller see Figure 13 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 19 of 25 NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 VDD VBBS A RPU RPU SCL SCL to the MCU from PCx2129 INT SDI SDI 9 SDO SDO tT INT CE SDA CE MCU PCx2129 100nF 7 Batt 100nF Vss aaa 005282 Fig 13 Application diagram timekeeping CLKOUT power management timestamp battery connected
8. of the most common methods through which packages are attached to Printed Circuit Boards PCBs to form electrical circuits The soldered joint provides both the mechanical and the electrical connection There is no single soldering method that is ideal for all IC packages Wave soldering is often preferred when through hole and Surface Mount Devices SMDs are mixed on one Printed Circuit Board PCB however it is not suitable for fine pitch SMDs Reflow soldering is ideal for the small pitches and high densities that come with increased miniaturization The PCA2129 and PCF2129 are intended for use in a reflow soldering process The reflow soldering process involves applying solder paste to a board followed by component placement and exposure to a temperature profile Leaded packages packages with solder balls and leadless packages are all reflow solderable Key characteristics in reflow soldering are e Board specifications including the board finish solder masks and vias e Package footprints including solder thieves and orientation e The moisture sensitivity level of the packages Package placement e Inspection and repair e Lead free versus SnPb soldering note that a lead free reflow process usually leads to higher minimum peak temperatures than a SnPb process thus reducing the process window e Solder paste printing issues including smearing release and adjusting the process window for a mix of large and small components on o
9. party customer s NXP does not accept any liability in this respect Export control This document as well as the item s described herein may be subject to export control regulations Export might require a prior authorization from competent authorities Non automotive qualified products Unless this data sheet expressly states that this specific NXP Semiconductors product is automotive qualified the product is not suitable for automotive use It is neither qualified nor tested in accordance with automotive testing or application requirements NXP Semiconductors accepts no liability for inclusion and or use of non automotive qualified products in automotive equipment or applications In the event that customer uses the product for design in and use in automotive applications to automotive specifications and standards customer a shall use the product without NXP Semiconductors warranty of the product for such automotive applications use and specifications and b whenever customer uses the product for automotive applications beyond NXP Semiconductors specifications such use shall be solely at customer s own risk and c customer fully indemnifies NXP Semiconductors for any liability damages or failed product claims resulting from customer design and use of the product for automotive applications beyond NXP Semiconductors standard warranty and NXP Semiconductors product specifications Translations A non English t
10. 014 5 of 25 NXP Semiconductors AN1 1 1 86 AN11186 Application and soldering information for the PCA2129 and PCF2129 Once the temperature is set and is stable it is necessary to wait until the PCA2129 and PCF2129 have performed the temperature measurement then the frequency can be measured at the CLKOUT pin To perform quicker measurements it is recommended to select the temperature measurement period of 30 seconds TCR 1 0 11 In summary for an accurate evaluation of the frequency stability the following operating flow is recommended Power on with Vpp 3 3 V Wait until the 32 768 kHz signal is available at the CLKOUT pin Program a COF 2 0 value other than the default for example COF 2 0 110 which corresponds to fe_kout 1 Hz Program TCR 1 0 11 which corresponds to a temperature measurement period equal to 30 seconds Set the target temperature Wait until temperature is stable Wait until the temperature measurement is executed 30 seconds after the temperature is stable Measure the frequency at the CLKOUT pin All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 6 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 4 Reflow soldering 4 1 4 2 AN11186 Introduction to reflow soldering Soldering is one
11. 1 16384 50 50 010 8192 50 50 011 4096 50 50 100 2048 50 50 101 1024 50 50 110 1 50 50 111 CLKOUT high Z 1 Duty cycle definition HIGH level time LOW level time The selection of fe_kout 32 768 kHz COF 2 0 000 default value leads to lower accuracy It is therefore recommended to select a frequency other than the default value of 32 768 kHz for accurate frequency measurements The most accurate frequency measurement occurs when 1 Hz is selected In order to be able to adjust the clock with accuracy better than 1 ppm the frequency counter used to check the output at CLKOUT should have at least an 8 digit reading Furthermore for accurate evaluation of the frequency stability over temperature it is important that the frequency measurement is executed when the temperature is stable and the PCA2129 and PCF2129 performed the temperature measurement The PCA2129 and PCF2129 measure the temperature immediately after power on and then periodically with a period set by the temperature conversion rate bits TCR 1 0 in register CLKOUT_ctl OFh Table 2 Temperature measurement interval TCR 1 0 Temperature measurement interval ool 4 min 01 2 min 10 1 min 11 30 seconds 1 Default value All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2
12. AO 3 0 0110 2 A frequency measurement see Section 3 should be performed after the final assembly of the board if the soldering was processed multiple times the soldering was not made according to the recommended temperature profile the best result in accuracy should be achieved Then the offset with the appropriate value given in Table 4 should be programmed into AOJ 3 0 Deviations caused by assembly steps or due to production tolerances can be compensated with it AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 9 of 25 NXP Semiconductors AN1 11 86 4 5 AN11186 Application and soldering information for the PCA2129 and PCF2129 Table 4 Typical frequency correction at 25 C AO 3 0 ppm Decimal Binary 0 0000 8 1 0001 7 2 0010 6 3 0011 5 4 0100 4 5 0101 3 6 0110 2 7 0111 1 8 100011 0 9 1001 1 10 1010 2 11 1011 3 12 1100 4 13 1101 5 14 1110 6 15 1111 7 1 Default value Optimization at room temperature Many applications operate in a temperature range of 15 C to 35 C most of the time Therefore it is preferred to optimize the accuracy for this range There is a simple way to do this fine tuning 1 Measure the frequency at about 25 C 2 Calculate the
13. cations that are described herein for any of these products are for illustrative purposes only NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification AN11186 All information provided in this document is subject to legal disclaimers Customers are responsible for the design and operation of their applications and products using NXP Semiconductors products and NXP Semiconductors accepts no liability for any assistance with applications or customer product design It is customer s sole responsibility to determine whether the NXP Semiconductors product is suitable and fit for the customer s applications and products planned as well as for the planned application and use of customer s third party customer s Customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products NXP Semiconductors does not accept any liability related to any default damage costs or problem which is based on any weakness or default in the customer s applications or products or the application or use by customer s third party customer s Customer is responsible for doing all necessary testing for the customer s applications and products using NXP Semiconductors products in order to avoid a default of the applications and the products or of the application or use by customer s third
14. d e When cover 2 is opened the push button 2 is closed and the TS pin is driven to ground Event 2 TSF1 and TSF2 are both set date and time is registered 5 5 Timekeeping applications For using the time keeping functions of the PCA2129 and PCF2129 see Figure 7 CLKOUT is disabled COF 2 0 111 e The power management functions are disabled PWRMNG 2 0 111 and pin Vpar is tied to ground e The timestamp detection is disabled TSOFF 1 Timekeeping is very accurate due to the temperature compensation The power consumption is minimized VDD to the MCU INT PCx2129 100 nF Vss aaa 005271 Fig 7 Application diagram timekeeping If CLKOUT is enabled during time keeping as described in Section 5 6 to Section 5 10 the best accuracy is achieved if a CLKOUT frequency other than the default value of 32 768 kHz is selected AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 14 of 25 NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 5 6 Timekeeping and CLKOUT Figure 8 shows the PCA2129 and PCF2129 used for timekeeping and CLKOUT functions e CLKOUT is connected to Vpp using a pull up resistor e CLKOUT is enabled at 32 768 kHz by default after start up COF 2 0 000 e The power management func
15. er Manual for NXP Real Time Clocks PCF85x3 PCA8565 and PCF2123 PCA2125 AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 21 of 25 NXP Semiconductors AN11186 Application and soldering information for the PCA2129 and PCF2129 8 Legal information 8 1 Definitions Draft The document is a draft version only The content is still under internal review and subject to formal approval which may result in modifications or additions NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information 8 2 Disclaimers Limited warranty and liability Information in this document is believed to be accurate and reliable However NXP Semiconductors does not give any representations or warranties expressed or implied as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information NXP Semiconductors takes no responsibility for the content in this document if provided by an information source outside of NXP Semiconductors In no event shall NXP Semiconductors be liable for any indirect incidental punitive special or consequential damages including without limitation lost profits lost
16. ights reserved Application note Rev 3 18 December 2014 16 of 25 NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 5 8 Timekeeping CLKOUT and timestamp Figure 10 shows the PCA2129 and PCF2129 used for timekeeping CLKOUT and timestamp functions e CLKOUT is connected to Vpp using a pull up resistor e CLKOUT is enabled at 32 768 kHz by default after start up COF 2 0 000 e The power management functions are disabled PWRMNG 2 0 111 and pin Vgaris tied to ground e The timestamp detection is enabled by default TSOFF 0 see Figure 6 VoD RPU RPU to the MCU INT IFS PCx2129 TS ie CLKOUT tor or Vss Te oo 100 nF Vss lt lt hai aaa 005275 Fig 10 Application diagram timekeeping CLKOUT and timestamp AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 17 of 25 NXP Semiconductors AN11186 Application and soldering information for the PCA2129 and PCF2129 5 9 Timekeeping CLKOUT power management and timestamp For using the timekeeping power management CLKOUT and timestamp functions of the PCA2129 and PCF2129 see Figure 11 CLKOUT is connected to Vpp using a pull up resistor CLKOUT is enabled at 32 768 kHz by default after
17. ights reserved For more information please visit http www nxp com For sales office addresses please send an email to salesaddresses nxp com Date of release 18 December 2014 Document identifier AN11186
18. ne board e Reflow temperature profile see Figure 3 this profile includes preheat Tg reflow in which the board is heated to the peak temperature Tp and cooling down It is imperative that the peak temperature is high enough for the solder to make reliable solder joints a solder paste characteristic In addition the peak temperature must be low enough that the packages and or boards are not damaged For further information on reflow soldering IC refer to Ref 1 AN10365 Reflow soldering of PCA2129 and PCF2129 The PCA2129 and PCF2129 are intended for use in a lead free reflow soldering process classified in accordance with the Ref 3 IPC JEDEC J STD 020 Figure 3 shows the reflow soldering temperature profile according to Ref 3 IPC JEDEC J STD 020 used for the qualification of the PCA2129 and PCF2129 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 7 of 25 AN11186 Application and soldering information for the PCA2129 and PCF2129 NXP Semiconductors A temperature max ramp up rate 3 C s Tp t ei a Catala aiaa Settee Tc max ramp down rate 6 C s TL Ts max preheat area t t Ts min i 25 C gt time le tdur from 25 C to peak gt 013aaa168 Figure not drawn to scale The approp
19. nse 2 Uncompensated typical tuning fork crystal frequency Fig 1 Typical characteristic of frequency with respect to temperature of PCF2129AT 013aaa345 40 Frequency stability ppm 40 20 0 20 40 60 80 100 Temperature C Vpop Or Vegar 3 3 V 1 Typical temperature compensated frequency response 2 Uncompensated typical tuning fork crystal Fig 2 Typical characteristic of frequency with respect to temperature of PCA2129T and PCF2129T All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 4 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 Remark For Vpp or Vegar other than 3 3 V a frequency shift of 1 ppm V has to be expected e For information about frequency correction see Section 4 4 3 Frequency measurement AN11186 The frequency stability can be evaluated by measuring the frequency of the square wave signal available at the output pin CLKOUT The frequency signal at pin CLKOUT is controlled by the COF 2 0 control bits in register CLKOUT_ctl OFh according to Table 1 Table 1 CLKOUT frequency selection COF 2 0 CLKOUT frequency Hz Typical duty cycle l 000 32768 60 40 to 40 60 00
20. offset to the nominal frequency of 32768 000 Hz 3 Program the correction value into AO 3 0 With this method it is possible to fine tune the RTC in steps of 1 ppm and ensure an accuracy of 1 ppm at room temperature All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 10 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 5 Application information 5 1 Assembly recommendations It is recommended to e take precautions when using the PCA2129 and PCF2129 with general purpose mounting equipment in order to avoid excessive shocks that could damage the integrated quartz crystal e avoid ultrasonic cleaning that could damage the integrated quartz crystal e avoid in the board layout running signal traces under the package unless a ground plane is placed between the package and the signal line 5 2 General application information In general it can be said that e the integration of the quartz crystal in the same package as the RTC has the following advantages elimination of crystal procurement issues elimination of concerns regarding the crystal parameters matching those of the RTC no more crystal PCB layout issues e the IFS pin must be connected to ground Vss to select the SPl bus e the IFS pin must be connected to the BBS pin to selec
21. onality of the battery switch over is limited by the fact that the power supply Vpp is monitored every 1 ms in order to save power consumption Considering that the battery switch over threshold value Vth sw bat s typically 2 5 V the power management operating limit Vpp min is 1 8 V and that Vpp is monitored every 1 ms the battery switch over works properly in all cases where Vpp falls with a rate lower than 0 7 V ms as shown in Figure 4 v 30 013aaa396 DD v Vth sw bat 2 5 V gt 0 7 V 2 0 Power management i PEE REEE E E es operating limit 1 8 V 1 0 0 0 1 ms sampling and comparing rate ms Fig 4 Supply voltage with respect to sampling and comparing rate In an application where during power down the current consumption on pin Vpp is e inthe range of a few uA a capacitor of 100 nF on pin Vpp is enough to allow a slow power down and the proper functionality of the battery switch over e inthe range of a few hundreds of uA the value of the capacitor on pin Vpp must be increased to force a falling gradient of less than 0 7 V ms on pin Vpp to assure the proper functionality of the battery switch over e higher than some mA it is recommended to add an RC network on the Vpp pin as shown in Figure 5 A series resistor of 330 Q and a capacitor of 6 8 uF assure the proper functionality of the battery switch over even with very fast Vpp slo
22. pe Note that e itis not suggested to assemble a series resistor higher than 1 KQ because it would cause a large voltage drop e lower values of capacitors are possible depending on the Vpp slope in the application 1 Like in the case of no interface activity and or early power fail detection functions that allow the microcontroller to perform early backup operations and to set power down modes 2 Like in the case of interface activity AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 12 of 25 NXP Semiconductors AN1 1 1 86 AN11186 Application and soldering information for the PCA2129 and PCF2129 T Vpp board I PCx2129 aaa 005269 Fig 5 RC network on pin Vpp 5 4 Timestamp applications The most common application of the timestamp function is a tamper detection date and time are stored when the cover of the equipment is opened A push button is attached to the cover in such a way that when the cover is opened the button is pushed mechanical connection the button is connected to the timestamp input pin so that when the button is pushed the timestamp circuit detects the event sets a flag and stores the date and time in internal registers The timestamp function integrated in the PCA2129 and PCF2129 allows double tamper detection in an application
23. ranslated version of a document is for reference only The English version shall prevail in case of any discrepancy between the translated and English versions 8 3 Trademarks Notice All referenced brands product names service names and trademarks are the property of their respective owners NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 22 of 25 NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 9 Tables Table 1 CLKOUT frequency selection 5 Table 2 Temperature measurement interval 5 Table 3 Values of reflow temperature profile 8 Table 4 Typical frequency correction at 25 C 10 Table 5 Abbreviations 2 00005 20 AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 23 of 25 NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 10 Figures Fig 1 Typical characteristic of frequency with respect to temperature of PCF2129AT 4 Fig 2 Typical characteristic of frequency with respect to temperature of PCA2129T and PCF2129T 4 Fig 3 Reflow temperature profile 8 Fig 4 Supply voltage with respect to sampling and comparing rate
24. riate values for this graph are shown in Table 3 Remark The reflow profile in this document is for classification preconditioning and not meant to specify board assembly profiles Actual board assembly profiles should be developed based on specific process needs and board designs but must not exceed the parameters shown in Table 3 Fig 3 Reflow temperature profile Table 3 Values of reflow temperature profile All temperatures refer to the center of the package measured on the package body surface that is facing up during the reflow soldering process Symbol Value Unit Tp 260 C TL 217 C Te 255 C Ts max 200 C T min 150 C tp 30 S tL 60 to 150 s ts 60 to 120 s tdur max 480 s Recommendations 1 The reflow soldering profile shown in Figure 3 is recommended A full convection reflow system capable of maintaining the reflow profile of Figure 3 is recommended 2 The peak temperature Tp of the reflow soldering process must not exceed 260 C If the temperature exceeds 260 C the characteristics of the crystal oscillator is degraded or the device may even be damaged AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 8 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 3 The time
25. savings business interruption costs related to the removal or replacement of any products or rework charges whether or not such damages are based on tort including negligence warranty breach of contract or any other legal theory Notwithstanding any damages that customer might incur for any reason whatsoever NXP Semiconductors aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the Terms and conditions of commercial sale of NXP Semiconductors Right to make changes NXP Semiconductors reserves the right to make changes to information published in this document including without limitation specifications and product descriptions at any time and without notice This document supersedes and replaces all information supplied prior to the publication hereof Suitability for use NXP Semiconductors products are not designed authorized or warranted to be suitable for use in life support life critical or safety critical systems or equipment nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury death or severe property or environmental damage NXP Semiconductors and its suppliers accept no liability for inclusion and or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and or use is at the customer s own risk Applications Appli
26. start up COF 2 0 000 A battery is attached to the Vgar pin see Section 5 3 The battery switch over and the battery low detection functions are enabled by default PWRMNG 2 0 000 The timestamp detection is enabled by default TSOFF 0 see Figure 6 Fig 11 VDD RPu RPU to the MCU INT PCx2129 Application diagram timekeeping CLKOUT power management and timestamp aaa 005277 AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 18 of 25 NXP Semiconductors AN1 1 1 86 AN11186 Application and soldering information for the PCA2129 and PCF2129 5 10 Timekeeping CLKOUT power management timestamp battery connected and supply of an external device Figure 12 shows the PCA2129 and PCF2129 used for timekeeping power management CLKOUT with a battery connected and supplying an external device e CLKOUT is connected to Vpp using a pull up resistor e CLKOUT is enabled at 32 768 kHz by default after start up COF 2 0 000 e A battery is attached to the Vgar pin e The battery switch over and the battery low detection functions are enabled by default PWRMNG 2 0 000 see Section 5 3 e The timestamp detection is enabled by default TSOFF 0 see Figure 6 e BBS supplies an
27. t the I2C bus e a backup battery can be attached to the Vgar pin to enable the battery switch over when the main power Vpp fails If Vgar is not used it has to be connected to ground If Vepar is used one of the supplies Vgart or Vpp has to be turned on before the other e the battery backed voltage Vggs can be used to supply an external RAM to retain RAM data in battery backup mode A low leakage decoupling capacitor should be connected from BBS to Vgs suggested value is 1 nF max 100 nF If BBS is not used to supply an external IC the decoupling capacitor between the BBS and Vss pins must always be connected CLKOUT and INT are open drain active LOW outputs which require external pull up resistors maximum pull up voltage is 5 5 V e the timestamp input pin TS can be connected to a push button for tamper detection see Section 5 4 5 2 1 Current consumption Current consumption is reduced if the power management functions are disabled PWRMNG 2 0 111 In that case the e battery switch over function is disabled e battery low detection is disabled e only one power supply Vpp is used AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 11 of 25 NXP Semiconductors AN1 1 1 86 Application and soldering information for the PCA2129 and PCF2129 5 3 Battery switch over applications The functi
28. tions are disabled PWRMNG 2 0 111 and pin Vgar is tied to ground e The timestamp detection is disabled TSOFF 1 VDD RPU RPu to the MCU INT IFS PCx2129 dau CLKOUT tne V to 100 nF SS 100 nF Vss ad _ lt aaa 005272 Fig 8 Application diagram timekeeping and CLKOUT AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 15 of 25 NXP Semiconductors AN1 11 86 Application and soldering information for the PCA2129 and PCF2129 5 7 Timekeeping CLKOUT and power management For using the timekeeping and power management functions of the PCA2129 and PCF2129 see Figure 9 CLKOUT is connected to Vpp using a pull up resistor CLKOUT is enabled at 32 768 kHz by default after start up COF 2 0 000 A battery is attached to the Vgar pin The battery switch over and the battery low detection functions are enabled by default PWRMNG 2 0 000 The timestamp detection is disabled TSOFF 1 Fig 9 Application diagram timekeeping CLKOUT and power management VDD RPU to the MCU INT IFS CLKOUT TUL Vss Batt 100 nF Vss aaa 005273 AN11186 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All r
29. ut slows down when the temperature deviates see graph no 2 in Figure 1 and Figure 2 The PCA2129 and PCF2129 are CMOS Real Time Clock RTC and calendar ICs They have an integrated Temperature Compensated Crystal Xtal Oscillator TCXO based on an integrated 32 768 kHz tuning fork quartz crystal The PCA2129 and PCF2129 are optimized for very high accuracy and very low power consumption They compensate automatically for temperature dependent frequency deviations see Figure 1 and Figure 2 For further information e g pinning diagram and register organization refer to the appropriate data sheets Ref 5 PCA2129 and Ref 6 PCF2129 All information provided in this document is subject to legal disclaimers NXP Semiconductors N V 2014 All rights reserved Application note Rev 3 18 December 2014 3 of 25 NXP Semiconductors AN11186 Application and soldering information for the PCA2129 and PCF2129 2 Frequency stability and time accuracy AN11186 Figure 1 and Figure 2 show the typical frequency stability of the PCA2129 and PCF2129 with respect to the temperature in comparison to an uncompensated tuning fork crystal 013aaa593 40 Frequency stability ppm 5 ppm 3 ppm H 5 ppm 40 20 0 20 40 60 80 100 Temperature C Vpop Or Vegar 3 3 V 1 Typical temperature compensated frequency respo
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