BQ76952: Design Stackable BMS using TWO BQ76952 IC. Need you support to remove LD Pin Circuit.

Embedded Developer

Part Number: BQ76952
Other Parts Discussed in Thread: TIDA-010247

Dear TI team,

I am designing 24S BMS using your reference design TIDA-010247, I don't want to use the LD pin circuit mentioned in your design ref some requirement issue.

So can tie the LD pin of both AFE to each ground directly & DNP some components as I attached.

1) D22 replace with 0ohm resistance.

2) D20 replace with 0ohm resistance.

3) DNP: R148,D21,Q41,R149,Q46,R156,D25,R164,R155,D24,R163,D23

5 months ago

0 Jose Couso 5 months ago

TI__Genius 15390 points

Hello,

I am looping in the person who created this design for better support.

Regards,
Jose Couso

0 Ryan Tan 5 months ago in reply to Jose Couso

TI__Intellectual 2896 points

Hi,

we have released an app note to explain more details of TIDA-010247, you may want to see why we design the discrete circuits.

https://www.ti.com/lit/an/sluaan9/sluaan9.pdf?ts=1681291503831&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FTIDA-010247

In my mind, one potential issue is if Q47 is on to turn off discharge MOSFET, it will draw current from TOP_DSG and dissipate charge pump.

Ryan Tan

0 Embedded Developer 5 months ago in reply to Ryan Tan

Prodigy 150 points

Hi Ryan,

Thanks for your valuable feedback.

I have made some changes in the circuit as per the attached configuration and found no voltage drains in the charge pump in the case of Q47 ON .

I am writing to you for your feedback.Could i go ahead with this circuit

0 Ryan Tan 5 months ago in reply to Embedded Developer

TI__Intellectual 2896 points

Hi,

I am not familiar with your real use cases and requirements. But if just look at the circuit above, I think there always be some leakage current flowing from BAT to UP_GND through D24, R155, D21, R147, TOP_DSG when DSG MOSFETs are in off status. And when Q47 is on, upper AFE charger pump will still be discharged to a little bit higher than BAT (gate voltage of Q41)

Ryan Tan

Power management

Power management forum

BQ76952: Design Stackable BMS using TWO BQ76952 IC. Need you support to remove LD Pin Circuit.