BQ76952: BQ76952 Predischarge\Precharge FETs switch sequence

Jiatu Li

Part Number: BQ76952

TI experts,

I see if enable PDSG function, "the device will first enable the PDSG FET, then transition to turn on the DSG FET and turn off the PDSG FET". What;s the time interval between turn on DSG FET and turn off PDSG FET? Can I adjust it?

Besides, I didn't see PCHG and CHG turn on/off sequence in BQ76952 TRM. When enable PCHG function and reach out either PCHG timeout or Precharge Stop Voltage condition, when should CHG FET turn on and PCHG FET turn off? What's the time interval? Can I adjust it?

over 1 year ago

0 Caleb Perez over 1 year ago

TI__Genius 11315 points

Hey Jiatu,

The time between turn on and turn off is completely dependent on your FET turn off and turn on circuit. I believe the BQ76952 will try to turn the FETs off as soon as it sees that the discharge FET is on. This time is not adjustable. The same applies to PCHG and CHG.

Thanks,
Caleb

0 Jiatu Li over 1 year ago in reply to Caleb Perez

Prodigy 120 points

Hi Caleb,

Thanks for your comments. But I really care about is after BQ76952 reach the condition to exit precharge/predischarge mode, after CHG/DSG FET turns on, when will PCHG/PDSG FET turn off? How long is this time interval? Could I adjust this?

0 Caleb Perez over 1 year ago in reply to Jiatu Li

TI__Genius 11315 points

Hey Jiatu,

The time between CHG/DSG FET on and PCHG PDSG FET off varies. Our data suggests a time between 250 to 500ms.

Thanks,
Caleb

0 Jiatu Li over 1 year ago in reply to Caleb Perez

Prodigy 120 points

Hi Caleb,

Understood, thanks very much for your help! I think this time interval is enough for my CHG/DSG FET to fully turn on before PCHG/PDSG FET turn off.

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BQ76952: BQ76952 Predischarge\Precharge FETs switch sequence