BQ76930: Help to review the schematic and two questions

Walsh

Intellectual 950 points

Part Number: BQ76930

Hi Experts:

BQ76930 BMS--48V50Ah.pdf

Hi Experts:

Could you help to review the attached schematic of BQ7693003 and give some advise?

Spec:

16S 48V/50Ah; LiFePO4 battery

additional two questions:

1. the application is 16S batteries and 2 BQ76930 is 20 interface. How to deal with the remaining 4 interface?

2. Will Q23 and Q11 cause damage to BQ76930?

Thanks,

Walsh

over 4 years ago

0 Matt Sunna over 4 years ago

TI__Guru* 80773 points

Hi Walsh,

Table 25 in the BQ76930 datasheet shows how to deal with the unused cell input connections. Refer to the first column of this table for configuring 6 cells.

Why do you think Q23 and Q11 will cause damage to the IC? Section 9 of the BQ769x0 Top Ten Design Consideration document (https://www.ti.com/lit/an/slua749a/slua749a.pdf) has a detailed discussion on the REGSRC supply circuit.

Best regards,

Matt

0 Walsh over 4 years ago in reply to Matt Sunna

Intellectual 950 points

Hi Matt:

Thanks a lot for your reply. another question, could you help to introduce the advantages of using N-MOS and P-MOS respectively in the below position.

PS:

TI 20S reference design use P-MOS

TI Application report use N-MOS

Thanks.

Walsh

0 Walsh over 4 years ago in reply to Walsh

Intellectual 950 points

0 Walsh over 4 years ago in reply to Walsh

Intellectual 950 points

upload the picture

0 Matt Sunna over 4 years ago in reply to Walsh

TI__Guru* 80773 points

Hi Walsh,

The BQ769x0 Top Ten Design Considerations document discusses the two options (see Section 4 on Cell Balancing). I believe that some customers have selected P-FETs in the past because they were able to find them at lower cost. I'm not sure if that is still the case.

Best regards,

Matt

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BQ76930: Help to review the schematic and two questions