BQ76952: When the current sense resistance is 0.5 milliohms, bq76952 cannot enter sleep mode. What adjustments does FW need to do?

jmyang

Part Number: BQ76952

TI experts,

When the current sense resistance is 0.5 milliohms, bq76952 cannot enter sleep mode. What adjustments does FW need to do?

I read the chip specification of bq76952 which suggests that it can support below 1 milliohm.

At present, after changing the current sense resistance to 1 milliohm, bq76952 can enter sleep mode, but the SRN and SRP voltages will exceed 200mV when short-circuited.

over 4 years ago

0 Matt Sunna over 4 years ago

TI__Guru* 81034 points

Hi JM,

You can use a 0.5 milliohm sense resistor with this device. You will need to change the CC Gain parameter setting for the new resistor value though. This should resolve the issue you are seeing.

Best regards,

Matt

0 jmyang over 4 years ago in reply to Matt Sunna

Expert 1186 points

hI Matt,

Are you referring to the parameters in the red circle below? I use a 0.5 milliohm resistor and then calibrate it. This CC Gain will follow the calibration change and cannot be fixed. Then bq76952 cannot go to sleep.

0 Matt Sunna over 4 years ago in reply to jmyang

TI__Guru* 81034 points

Hi JM,

Yes, these are the correct parameters.

There is also the Sleep Current parameter which should be set according to your application. Also, the WK_SPD bits in the Power Config register should be set to '00' - this will help avoid accidental wakeup due to noise.

Regards,

Matt