BQ76952: TS3 pin connected to NTC and configured as an ADCIN doesn't read the temperature values sometime.

Chandana B V

Part Number: BQ76952

Tool/software:

I'm configuring TS3 pin and TS1 Pin to be used as ADCIN pin. These two pins have an external NTC connected to them.

I can successfully read the voltage readings from register TS1 Temperature (0x70) and TS3 Temperature(0x74) most of the times.

But occasionally TS3 Temperature register(0x74) reads back 0x00, when this happen, I measured the voltage on the TS3 pin, the voltage reads 0x00 all the time.

When this issue happens, I see TS1 Temperature read normally, and I can also see waveforms on the TS1 pin and all other reading like Cell voltage read back normally( AFE is not in sleep/shutdown mode).

Below are the few things I made sure to check when I observed the issue with TS3 read,
- AFE is in Normal mode (VCell0-15 read normally. TS1 read is also normal)
- Read back the configuration from TS3 pin config (0x92FF) register to ensure the configurations are proper.
- Make sure the capacitor

Below are the steps and register configurations I used,
- Enter config mode with command 0x0090
- Ensure Device in config mode by reading back Batt status register
- Configure REG0 and REG13 register
- Set, TS1PINCONFIG @ 0x92FD = 0x33
- Set, TS3PINCONFIG @ 0x92FD = 0x33
- Exit config mode
- read back the TS1 and TS3 pin config to ensure 0x33 is written.
- read the voltage measurements from the registers TS1(0x70) and TS3(0x74)

I've tried quite a few workarounds but none of it worked.

Appreciate any help/suggestions to identify the issue.

I'm also attaching the logs I captured using logic analyzer when normal and abnormal behavior was observed.

Fullscreen Data_Log_TS3_Normal.txt Download

Time [s],Packet ID,Address,Data,Read/Write,ACK/NAK
3.869430000000000,0,0x08,0x3E,Write,NAK
3.889445000000000,0,0x08,0x3E,Write,ACK
3.889718000000000,0,0x08,0x34,Write,ACK
3.889837000000000,0,0x08,0x01,Write,ACK
3.890044000000000,0,0x08,0x92,Write,ACK
3.890180000000000,0,0x08,0xF7,Write,ACK
3.890390000000000,0,0x08,0x80,Write,ACK
3.890508000000000,0,0x08,0x89,Write,ACK
3.890715000000000,0,0x08,0x2C,Write,ACK
3.890833000000000,0,0x08,0xC4,Write,ACK
3.892399000000000,0,0x08,0x60,Write,ACK
3.892871000000000,0,0x08,0x8D,Write,ACK
3.892989000000000,0,0x08,0xFD,Write,ACK
3.893196000000000,0,0x08,0x06,Write,ACK
3.893332000000000,0,0x08,0x12,Write,ACK
3.912538000000000,0,0x08,0x3E,Write,ACK
3.912660000000000,0,0x08,0x37,Write,ACK
3.912778000000000,0,0x08,0x08,Write,ACK
3.912985000000000,0,0x08,0x92,Write,ACK
3.913120000000000,0,0x08,0xF7,Write,ACK
3.913329000000000,0,0x08,0x01,Write,ACK
3.913447000000000,0,0x08,0x07,Write,ACK
3.915498000000000,0,0x08,0x60,Write,ACK
3.915619000000000,0,0x08,0x35,Write,ACK
3.915737000000000,0,0x08,0xDC,Write,ACK
3.915944000000000,0,0x08,0x05,Write,ACK
3.916079000000000,0,0x08,0x1B,Write,ACK
3.935490000000000,0,0x08,0x3E,Write,ACK
3.935613000000000,0,0x08,0x36,Write,ACK
3.935730000000000,0,0x08,0x0F,Write,ACK
3.935937000000000,0,0x08,0x92,Write,ACK
3.936072000000000,0,0x08,0xF7,Write,ACK
3.936785000000000,0,0x08,0xDD,Write,ACK
3.936904000000000,0,0x08,0x1D,Write,ACK
3.938450000000000,0,0x08,0x60,Write,ACK
3.938572000000000,0,0x08,0x5A,Write,ACK
3.938690000000000,0,0x08,0xD6,Write,ACK
3.938897000000000,0,0x08,0x05,Write,ACK
3.939032000000000,0,0x08,0x1B,Write,ACK
3.958450000000000,0,0x08,0x3E,Write,ACK
3.958763000000000,0,0x08,0xFD,Write,ACK
3.958881000000000,0,0x08,0x70,Write,ACK
3.959087000000000,0,0x08,0x92,Write,ACK
3.959223000000000,0,0x08,0xF7,Write,ACK
3.959432000000000,0,0x08,0x33,Write,ACK
3.959550000000000,0,0x08,0x99,Write,ACK
3.959757000000000,0,0x08,0x33,Write,ACK
3.959875000000000,0,0x08,0x99,Write,ACK
3.960113000000000,0,0x08,0x33,Write,ACK
3.960231000000000,0,0x08,0x99,Write,ACK
3.961403000000000,0,0x08,0x60,Write,ACK
3.961905000000000,0,0x08,0xD7,Write,ACK
3.962023000000000,0,0x08,0x7C,Write,ACK
3.962229000000000,0,0x08,0x07,Write,ACK
3.962365000000000,0,0x08,0x15,Write,ACK
3.981517000000000,0,0x08,0x3E,Write,ACK
3.981639000000000,0,0x08,0x92,Write,ACK
3.981757000000000,0,0x08,0x7A,Write,ACK
3.981964000000000,0,0x08,0x00,Write,ACK
3.982099000000000,0,0x08,0x00,Write,ACK
3.991484000000000,0,0x08,0x3E,Write,ACK
3.991606000000000,0,0x08,0x34,Write,ACK
3.991724000000000,0,0x08,0x01,Write,ACK
3.991930000000000,0,0x08,0x92,Write,ACK
3.992066000000000,0,0x08,0xF7,Write,ACK
3.994444000000000,0,0x08,0x40,Write,ACK
3.994717000000000,0,0x08,0x80,Read,ACK
3.994833000000000,0,0x08,0x2A,Read,ACK
3.994969000000000,0,0x08,0x2C,Read,ACK
3.995085000000000,0,0x08,0xC4,Read,NAK
4.004531000000000,0,0x08,0x3E,Write,ACK
4.004653000000000,0,0x08,0x37,Write,ACK
4.004771000000000,0,0x08,0x08,Write,ACK
4.004978000000000,0,0x08,0x92,Write,ACK
4.005626000000000,0,0x08,0xF7,Write,ACK
4.007430000000000,0,0x08,0x40,Write,ACK
4.007704000000000,0,0x08,0x01,Read,ACK
4.007820000000000,0,0x08,0xA4,Read,NAK
4.017517000000000,0,0x08,0x3E,Write,ACK
4.018119000000000,0,0x08,0x36,Write,ACK
4.018238000000000,0,0x08,0x0F,Write,ACK
4.018445000000000,0,0x08,0x92,Write,ACK
4.018581000000000,0,0x08,0xF7,Write,ACK
4.020477000000000,0,0x08,0x40,Write,ACK
4.021200000000000,0,0x08,0xDD,Read,ACK
4.021316000000000,0,0x08,0xBE,Read,NAK
4.030425000000000,0,0x08,0x3E,Write,ACK
4.030547000000000,0,0x08,0xFD,Write,ACK
4.030665000000000,0,0x08,0x70,Write,ACK
4.030872000000000,0,0x08,0x92,Write,ACK
4.031009000000000,0,0x08,0xF7,Write,ACK
4.033369000000000,0,0x08,0x40,Write,ACK
4.034011000000000,0,0x08,0x33,Read,ACK
4.034126000000000,0,0x08,0x3A,Read,ACK
4.034262000000000,0,0x08,0x33,Read,ACK
4.034378000000000,0,0x08,0x99,Read,ACK
4.034514000000000,0,0x08,0x33,Read,ACK
4.034629000000000,0,0x08,0x99,Read,NAK
4.393518000000000,0,0x08,0x3E,Write,ACK
4.393640000000000,0,0x08,0xFD,Write,ACK
4.393758000000000,0,0x08,0x70,Write,ACK
4.394447000000000,0,0x08,0x92,Write,ACK
4.394583000000000,0,0x08,0xF7,Write,ACK
4.396417000000000,0,0x08,0x40,Write,ACK
4.396691000000000,0,0x08,0x33,Read,ACK
4.396807000000000,0,0x08,0x3A,Read,ACK
4.397237000000000,0,0x08,0x33,Read,ACK
4.397352000000000,0,0x08,0x99,Read,ACK
4.397489000000000,0,0x08,0x33,Read,ACK
4.397605000000000,0,0x08,0x99,Read,NAK
4.406390000000000,0,0x08,0x70,Write,ACK
4.407045000000000,0,0x08,0xC8,Read,ACK
4.407161000000000,0,0x08,0x34,Read,ACK
4.407297000000000,0,0x08,0x01,Read,ACK
4.407412000000000,0,0x08,0x07,Read,ACK
4.407549000000000,0,0x08,0xB5,Read,ACK
4.407664000000000,0,0x08,0x02,Read,ACK
4.407800000000000,0,0x08,0x04,Read,ACK
4.407916000000000,0,0x08,0x1C,Read,ACK
4.408053000000000,0,0x08,0xC5,Read,ACK
4.408168000000000,0,0x08,0x55,Read,ACK
4.408304000000000,0,0x08,0x01,Read,ACK
4.408419000000000,0,0x08,0x07,Read,NAK
4.756465000000000,0,0x08,0x3E,Write,ACK
4.756587000000000,0,0x08,0xFD,Write,ACK
4.756705000000000,0,0x08,0x70,Write,ACK
4.756911000000000,0,0x08,0x92,Write,ACK
4.757045000000000,0,0x08,0xF7,Write,ACK
4.759425000000000,0,0x08,0x40,Write,ACK
4.759698000000000,0,0x08,0x33,Read,ACK
4.759813000000000,0,0x08,0x3A,Read,ACK
4.759949000000000,0,0x08,0x33,Read,ACK
4.760065000000000,0,0x08,0x99,Read,ACK
4.760201000000000,0,0x08,0x33,Read,ACK
4.760317000000000,0,0x08,0x99,Read,NAK
4.769512000000000,0,0x08,0x70,Write,ACK
4.769785000000000,0,0x08,0xC8,Read,ACK
4.769900000000000,0,0x08,0x34,Read,ACK
4.770632000000000,0,0x08,0x01,Read,ACK
4.770748000000000,0,0x08,0x07,Read,ACK
4.770884000000000,0,0x08,0xB5,Read,ACK
4.770999000000000,0,0x08,0x02,Read,ACK
4.771135000000000,0,0x08,0x04,Read,ACK
4.771251000000000,0,0x08,0x1C,Read,ACK
4.771387000000000,0,0x08,0xC5,Read,ACK
4.771503000000000,0,0x08,0x55,Read,ACK
4.771639000000000,0,0x08,0x01,Read,ACK
4.771754000000000,0,0x08,0x07,Read,NAK
5.119523000000000,0,0x08,0x3E,Write,ACK
5.119645000000000,0,0x08,0xFD,Write,ACK
5.119763000000000,0,0x08,0x70,Write,ACK
5.119971000000000,0,0x08,0x92,Write,ACK
5.120107000000000,0,0x08,0xF7,Write,ACK
5.122422000000000,0,0x08,0x40,Write,ACK
5.122696000000000,0,0x08,0x33,Read,ACK
5.122812000000000,0,0x08,0x3A,Read,ACK
5.122948000000000,0,0x08,0x33,Read,ACK
5.123064000000000,0,0x08,0x99,Read,ACK
5.123201000000000,0,0x08,0x33,Read,ACK
5.123316000000000,0,0x08,0x99,Read,NAK
5.132509000000000,0,0x08,0x70,Write,ACK
5.132783000000000,0,0x08,0xC8,Read,ACK
5.132899000000000,0,0x08,0x34,Read,ACK
5.133035000000000,0,0x08,0x01,Read,ACK
5.133151000000000,0,0x08,0x07,Read,ACK
5.133288000000000,0,0x08,0xB5,Read,ACK
5.133403000000000,0,0x08,0x02,Read,ACK
5.133540000000000,0,0x08,0x04,Read,ACK
5.133655000000000,0,0x08,0x1C,Read,ACK
5.133792000000000,0,0x08,0xC5,Read,ACK
5.134384000000000,0,0x08,0x55,Read,ACK
5.134521000000000,0,0x08,0x01,Read,ACK
5.134636000000000,0,0x08,0x07,Read,NAK
5.482403000000000,0,0x08,0x3E,Write,ACK
5.482664000000000,0,0x08,0xFD,Write,ACK
5.482782000000000,0,0x08,0x70,Write,ACK
5.482990000000000,0,0x08,0x92,Write,ACK
5.483127000000000,0,0x08,0xF7,Write,ACK
5.485342000000000,0,0x08,0x40,Write,ACK
5.485809000000000,0,0x08,0x33,Read,ACK
5.485925000000000,0,0x08,0x3A,Read,ACK
5.486062000000000,0,0x08,0x33,Read,ACK
5.486178000000000,0,0x08,0x99,Read,ACK
5.486315000000000,0,0x08,0x33,Read,ACK
5.486431000000000,0,0x08,0x99,Read,NAK
5.495488000000000,0,0x08,0x70,Write,ACK
5.495763000000000,0,0x08,0xC8,Read,ACK
5.495878000000000,0,0x08,0x34,Read,ACK
5.496014000000000,0,0x08,0x01,Read,ACK
5.496130000000000,0,0x08,0x07,Read,ACK
5.496266000000000,0,0x08,0xB5,Read,ACK
5.496382000000000,0,0x08,0x02,Read,ACK
5.496518000000000,0,0x08,0x04,Read,ACK
5.496633000000000,0,0x08,0x1C,Read,ACK
5.496770000000000,0,0x08,0xC5,Read,ACK
5.496885000000000,0,0x08,0x55,Read,ACK
5.497022000000000,0,0x08,0x01,Read,ACK
5.497137000000000,0,0x08,0x07,Read,NAK
5.845475000000000,0,0x08,0x3E,Write,ACK
5.845597000000000,0,0x08,0xFD,Write,ACK
5.845715000000000,0,0x08,0x70,Write,ACK
5.846406000000000,0,0x08,0x92,Write,ACK
5.846542000000000,0,0x08,0xF7,Write,ACK
5.848374000000000,0,0x08,0x40,Write,ACK
5.848649000000000,0,0x08,0x33,Read,ACK
5.848764000000000,0,0x08,0x3A,Read,ACK
5.849402000000000,0,0x08,0x33,Read,ACK
5.849517000000000,0,0x08,0x99,Read,ACK
5.849654000000000,0,0x08,0x33,Read,ACK
5.849770000000000,0,0x08,0x99,Read,NAK
5.858369000000000,0,0x08,0x70,Write,ACK
5.858987000000000,0,0x08,0xC8,Read,ACK
5.859102000000000,0,0x08,0x34,Read,ACK
5.859239000000000,0,0x08,0x01,Read,ACK
5.859354000000000,0,0x08,0x07,Read,ACK
5.859491000000000,0,0x08,0xB5,Read,ACK
5.859606000000000,0,0x08,0x02,Read,ACK
5.859742000000000,0,0x08,0x04,Read,ACK
5.859857000000000,0,0x08,0x1C,Read,ACK
5.859994000000000,0,0x08,0xC5,Read,ACK
5.860109000000000,0,0x08,0x55,Read,ACK
5.860245000000000,0,0x08,0x01,Read,ACK
5.860361000000000,0,0x08,0x07,Read,NAK
6.208452000000000,0,0x08,0x3E,Write,ACK
6.208574000000000,0,0x08,0xFD,Write,ACK
6.208691000000000,0,0x08,0x70,Write,ACK
6.208898000000000,0,0x08,0x92,Write,ACK
6.209033000000000,0,0x08,0xF7,Write,ACK
6.211351000000000,0,0x08,0x40,Write,ACK
6.211625000000000,0,0x08,0x33,Read,ACK
6.211740000000000,0,0x08,0x3A,Read,ACK
6.211877000000000,0,0x08,0x33,Read,ACK
6.211992000000000,0,0x08,0x99,Read,ACK
6.212129000000000,0,0x08,0x33,Read,ACK
6.212244000000000,0,0x08,0x99,Read,NAK
6.221437000000000,0,0x08,0x70,Write,ACK
6.221711000000000,0,0x08,0xC8,Read,ACK
6.221826000000000,0,0x08,0x34,Read,ACK
6.221963000000000,0,0x08,0x01,Read,ACK
6.222514000000000,0,0x08,0x07,Read,ACK
6.222651000000000,0,0x08,0xB5,Read,ACK
6.222767000000000,0,0x08,0x02,Read,ACK
6.222903000000000,0,0x08,0x04,Read,ACK
6.223019000000000,0,0x08,0x1C,Read,ACK
6.223156000000000,0,0x08,0xC5,Read,ACK
6.223271000000000,0,0x08,0x55,Read,ACK
6.223408000000000,0,0x08,0x01,Read,ACK
6.223523000000000,0,0x08,0x07,Read,NAK
6.571487000000000,0,0x08,0x3E,Write,ACK
6.571609000000000,0,0x08,0xFD,Write,ACK
6.571728000000000,0,0x08,0x70,Write,ACK
6.571936000000000,0,0x08,0x92,Write,ACK
6.572073000000000,0,0x08,0xF7,Write,ACK
6.574386000000000,0,0x08,0x40,Write,ACK
6.574660000000000,0,0x08,0x33,Read,ACK
6.574776000000000,0,0x08,0x3A,Read,ACK
6.574913000000000,0,0x08,0x33,Read,ACK
6.575029000000000,0,0x08,0x99,Read,ACK
6.575166000000000,0,0x08,0x33,Read,ACK
6.575282000000000,0,0x08,0x99,Read,NAK
6.584411000000000,0,0x08,0x70,Write,ACK
6.584685000000000,0,0x08,0xC8,Read,ACK
6.584801000000000,0,0x08,0x34,Read,ACK
6.584937000000000,0,0x08,0x01,Read,ACK
6.585053000000000,0,0x08,0x07,Read,ACK
6.585190000000000,0,0x08,0xB5,Read,ACK
6.585305000000000,0,0x08,0x02,Read,ACK
6.585442000000000,0,0x08,0x04,Read,ACK
6.585557000000000,0,0x08,0x1C,Read,ACK
6.585694000000000,0,0x08,0xC5,Read,ACK
6.586325000000000,0,0x08,0x55,Read,ACK
6.586461000000000,0,0x08,0x01,Read,ACK
6.586577000000000,0,0x08,0x07,Read,NAK
6.934373000000000,0,0x08,0x3E,Write,ACK
6.934667000000000,0,0x08,0xFD,Write,ACK
6.934785000000000,0,0x08,0x70,Write,ACK
6.934992000000000,0,0x08,0x92,Write,ACK
6.935128000000000,0,0x08,0xF7,Write,ACK
6.937298000000000,0,0x08,0x40,Write,ACK
6.937695000000000,0,0x08,0x33,Read,ACK
6.937811000000000,0,0x08,0x3A,Read,ACK
6.937947000000000,0,0x08,0x33,Read,ACK
6.938063000000000,0,0x08,0x99,Read,ACK
6.938200000000000,0,0x08,0x33,Read,ACK
6.938315000000000,0,0x08,0x99,Read,NAK
6.947444000000000,0,0x08,0x70,Write,ACK
6.947719000000000,0,0x08,0xC8,Read,ACK
6.947835000000000,0,0x08,0x34,Read,ACK
6.947971000000000,0,0x08,0x01,Read,ACK
6.948087000000000,0,0x08,0x07,Read,ACK
6.948223000000000,0,0x08,0xB5,Read,ACK
6.948339000000000,0,0x08,0x02,Read,ACK
6.948475000000000,0,0x08,0x04,Read,ACK
6.948591000000000,0,0x08,0x1C,Read,ACK
6.948728000000000,0,0x08,0xC5,Read,ACK
6.948843000000000,0,0x08,0x55,Read,ACK
6.948980000000000,0,0x08,0x01,Read,ACK
6.949096000000000,0,0x08,0x07,Read,NAK

10 months ago

0 Chandana B V 10 months ago

Intellectual 340 points

Please pardon the typo in the question,

I'm writing/reading TS3 Pin Config from (0x92FF) and it does read back 0x33.

0 Alexis_H 10 months ago in reply to Chandana B V

TI__Genius 17975 points

Hello Chandana,

Thank you for sharing all of those images/logs with the logic analyzer. Just to double-check, with 0x33 configured, you wanted no polynomial to be used, just the raw ADC counts are reported?

Also, can you share with me the waveforms for TS1 and TS3, and the entire .gg file for your configuration?

Best Regards,
Alexis

0 Chandana B V 10 months ago in reply to Alexis_H

Intellectual 340 points

Hi Alexis,

1. I am programming the TS1 and TS3 pins to report the raw ADC counts, I do not want to use polynomial.

2. I'm using a custom board with AFE and a STM MCU, I'm using MCU to program the AFE via I2C and thus I do not have a .gg file. that's the reason I listed the read and write sequence. but below are all the registers, I'm configuring and their values.

Power Config Register (0x9234) = 0x2C80 //Power Config - Disable Sleep Mode by default, wake up speed set to 48ms, retain rest of settings as is
REG0 Config (0x9237) = 0x01 //Enable REG0
REG12_Config(0x9236) = 0xDD //REG12 Config' - Enable REG1 with 3.3V and REG2 with 3.3V output (0x0D for 3.3V, 0x0F for 5V)
TS1pinConfig(0x92FD) = 0x33 // Configure TS1 Pin as ADC Input--> 18K Pull up, Vref = 1.8V
TS3pinConfig(0x92FF) = 0x33 // Configure TS3 Pin as ADC Input--> 18K Pull up, Vref = 1.8V

3. I've also attached the TS1 and TS3 waveforms, when reading is normal, and reading is abnormal

0 Alexis_H 10 months ago in reply to Chandana B V

TI__Genius 17975 points

Hello Chandana,

Thank you for clarifying and sharing these waveforms. Do you mind sharing your schematic as well?

Best Regards,
Alexis

0 Chandana B V 10 months ago in reply to Alexis_H

Intellectual 340 points

Hi Alexis,

Thank you so much for your support.

unfortunately, I'm not allowed to share any part of the schematics for confidentiality reasons (apologies). I can answer any specific question you have on the schematic and for our schematic design we used TI eval board (EVM) design as reference. if the concern is the capacitor value recommended by TRM to measure the ADC pins, we use 3.3nF capacitor on both TS1 and TS3 pins and it's well withing the recommended limit.

0 Alexis_H 10 months ago in reply to Chandana B V

TI__Genius 17975 points

Hello Chandana,

Thanks for letting me know. I was thinking that it could potentially be a capacitor issue, but you've already clarified regarding it. This issue is very strange. Is it possible there is an issue with the device communication? Are you using it with CRC enabled? That should help prevent any corrupt readings. Can you capture this on a logic analyzer as well?

Best Regards,
Alexis

Power management

Power management forum

BQ76952: TS3 pin connected to NTC and configured as an ADCIN doesn't read the temperature values sometime.