This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ76907: COV and CUV delay time setting

Part Number: BQ76907

Tool/software:

Hello Sir:

We need your explanation on COV and CUV delay time.

If conversion-time setting is 2.93ms, and cell overrvoltage protection delay setting is 10 ADSCAN intervals. (balancing configuration is 01)

And out verified results is around 270ms, it's not meet our understand, we think which should be within 29.3ms. (ch1 is VC1, ch2 is VCHG(pin10))

If conversion-time setting is 1.46ms, and cell overvoltage protection delay setting is 10 ADSCAN intervals. (balancing configuration is 01)

And out verified results is around 140ms, it's not meet our understand, we think which should be within 14.6ms. (ch1 is VC1, ch2 is VCHG(pin10))

If conversion-time setting is 732us, and cell overvoltage protection delay setting is 10 ADSCAN intervals. (balancing configuration is 01)

And out verified results is around 90ms, it's not meet our understand, we think which should be within 7.3ms. (ch1 is VC1, ch2 is VCHG(pin10))

If conversion-time setting is 366us, and cell overvoltage protection delay setting is 10 ADSCAN intervals. (balancing configuration is 01)

And out verified results is around 60ms, it's not meet our understand, we think which should be within 3.6ms. (ch1 is VC1, ch2 is VCHG(pin10) )

Would you please provide explanation on it? and let us how to calculate the delay time.

Looking forward your feedback.

Thanks a lot.

  • Hello Statham,

    The conversion time for each cell is 2.93-ms (Assuming default settings). However, this is for a single cell, each ADSCAN is a measurement loop. This is described in Section 5.1.1 Voltage Measurement Schedule of the TRM

    So at the slowest settings each ADSCAN will take ~23.44-ms (Assuming the 2.93-ms conversion time and 7 cells) and will take ~2.928-ms at the fastest setting (If configured to do so, this is done by changing CVADC/SSADC speeds). So 10 ADSCANS will be ~234.4-ms at the slowest or ~29.28-ms at the fastest.

    However, if the part is in SLEEP mode, measurements are performed at a slower rate, once the part detects a fault condition, it will get out of SLEEP and into NORMAL mode to continue to perform measurements, this may also add some delay time as well.

    Is the part in SLEEP mode? If so, could they try these tests in NORMAL mode instead? What exactly are your settings? Your .gg.csv file would be good so I can check all your settings.

    Best Regards,

    Luis Hernandez Salomon