BQ76952: BQ76952

kentaro kiuchi

Prodigy 95 points

Part Number: BQ76952

I would like to use two BQ76952s to configure a protection function for 24 series cells.

Is this possible? If I use two ICs, how should I configure it?

over 3 years ago

0 Matt Sunna over 3 years ago

TI__Guru* 81034 points

Hi Kentaro,

Yes, this is possible. This can be done using low-side FETs described in this technical article: https://e2e.ti.com/blogs_/b/powerhouse/posts/how-to-stack-battery-monitors-for-high-cell-count-industrial-applications

Or it can be done using high-side FETs, but may be a little more complex. There is a TI Reference Design coming out in November that will be using this implementation.

Here is a previous E2E thread on this topic which may be helpful:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/991852/bq76952-stacking-two-ics

Best regards,

Matt

0 kentaro kiuchi over 3 years ago in reply to Matt Sunna

Prodigy 95 points

Hi Matt,

It is not in BQ76952 on the high side, but could you tell me the reason?

The device circled in red looks like an AND circuit, but is it correct to use an OR circuit?

+1 Matt Sunna over 3 years ago in reply to kentaro kiuchi

TI__Guru* 81034 points

Hi Kentaro,

If the DDSG and DCHG pins are programmed as logic high enables the FETs, then an AND circuit is needed (for example, if DDSG on either device is logic low, it will disable the DSG FET). DDSG and DCHG pins can also be configured as active low, so in this case OR logic would be needed.

For high-side FETs, the charge pump voltage of the top device is used to enable the FETs, but the DSG FET falls with the LD pin of the top device which should not drop all the way to the VSS of the lower device. This design gets a little more complex. The reference design will address issues like this and should be available in November.

Best regards,

Matt

0 kentaro kiuchi over 3 years ago in reply to Matt Sunna

Prodigy 95 points

Hi Matt,

thank you for your answer.

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BQ76952: BQ76952