BQ77915: 10 CELL BMS USING BQ7791506 - NOT WORKING - Please review my schematic

Anil Sudhakaran

Part Number: BQ77915

Hi,

Have made a board for 10 cell BMS cascading 2 numbers of BQ7791506 .

Mosfets are not getting enabled. When I check only the lower IC (configuring it as single BMS IC), Mosfets gate signals are OK. We already have a solution with single IC which is in production.

Could you please review the schematic and suggest what could be wrong ? I would like to send the schematic privately. Please enable private messaging to send schematic.

Thanks & Regards,

Anil

over 4 years ago

0 Matt Sunna over 4 years ago

TI__Guru* 81034 points

Hi Anil,

I sent you a connection request. You should be able to send me your schematic in a private message.

Hopefully you have also seen this stacking document for the BQ77915: https://www.ti.com/lit/an/slua906a/slua906a.pdf

Best regards,

Matt

0 Anil Sudhakaran over 4 years ago in reply to Matt Sunna

Expert 1125 points

HI Matt,

Thanks for the quick reply.

Sent the schematic to you now in a private message. Please review and comment.

Have seen the document you mentioned .

Regards,

Anil

0 Matt Sunna over 4 years ago in reply to Anil Sudhakaran

TI__Guru* 81034 points

Hi Anil,

I see issues with some of the component values in the schematic - I sent my feedback in response to the private message, but will repeat here in case others have the same issue to debug:

CTRC/CTRD resistor values should be 10M (not 1k)
LPWR to PRES resistor should be 10k (not 0)
OCDP resistor for upper device should be 10M (not 100)
OCDP resistor for lower device is not valid (see Table 9-3 in datasheet)

Best regards,

Matt

0 Anil Sudhakaran over 4 years ago in reply to Matt Sunna

Expert 1125 points

Thanks Matt for the detailed review and pointing out the component values mistakes.

Yes. Did the changes you mentioned and also made our ALL component values exactly similar to the circuit you provided in https://www.ti.com/lit/an/slua906a/slua906a.pdf.

Basic charging and discharging functionalities are working fine now. Seeing some issue in under voltage cutoff. Checking those and remaining functionalities now.

Will update on the remaining test results in 3-4 days. Will take your help for any other issues that we came across in the remaining tests.

Regards,

Anil

0 Matt Sunna over 4 years ago in reply to Anil Sudhakaran

TI__Guru* 81034 points

Glad to hear this Anil.

Best regards,

Matt

0 Anil Sudhakaran over 4 years ago in reply to Matt Sunna

Expert 1125 points

Hi Matt,

Al functionalities tested and are working fine.

Going for pilot production next.

Thank you.

Regards,

Anil

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BQ77915: 10 CELL BMS USING BQ7791506 - NOT WORKING - Please review my schematic