BQ76952: Is there a risk of damaging the MOS by using a charge pump to drive the high-side MOS?

Hailiang Zhang

Part Number: BQ76952

Hi Team，

Could you pls help analyze the following questions?

Is there a risk of damaging the MOS by using a charge pump with a weak driving capability to drive the high-side MOS?

As mentioned in some external application reports, when the charge pump drives the MOS, the drive signal may be lost due to insufficient driving capability, or the MOS will remain on when there is a OCD or SCD, resulting in damage to the MOS. My customer asked if this could be the cause of the issue described in another e2e thread, " (+) BQ76952: DFET damage during short-term high-current discharge - Power management forum - Power management - TI E2E support forums"? How to verify it?

Many thanks.

Regards,

Hailiang

over 2 years ago

0 Matt Sunna over 2 years ago

TI__Guru* 79123 points

Hi Hailiang,

Since we already have an email communication in progress on this topic, I will respond to our email discussion and close this thread.

Best regards,

Matt

0 Hailiang Zhang over 2 years ago in reply to Matt Sunna

TI__Expert 6065 points

Hi Matt，

For the DFET damage issue, customers tested on E-bikes, and the failure was reproduced by giving fuel to acceleration while braking. It can be seen that the VGS voltage gradually drops from 11V to 0V, When Vgs is small, the discharge FET is not fully turned on, which may cause the FET to burn out. I sent an email to describe the details, could you analyze and give your suggestions as soon as possible for this urgent issue?