BQ40Z80: BQ40Z80 External Cell Balancing

user44411751

Intellectual 940 points

Part Number: BQ40Z80

The bq40z80 external cell balance cell 1 use PMOS, the others are NMOS, why are they use different type MOSFET?

over 5 years ago

0 Onyx Ahiakwo over 5 years ago

TI__Guru* 76230 points

Pls see section 8.3.6.5 of the data sheet.

thanks

Onyx

0 user44411751 over 5 years ago in reply to Onyx Ahiakwo

Intellectual 940 points

I think cell1 to cell6 should be the same driver. But the cell1 use PMOS, the others are NMOS in the TRM sheet.

0 Damian Lewis over 5 years ago in reply to user44411751

TI__Mastermind 34775 points

The bottom cell doesn't have a series 1k resistor to VSS to set the cell balancing FET gate bias, if it was an NMOS when the controller FET turns on. It pulls the gate to VSS when turned on hence PMOS has to be used.

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BQ40Z80: BQ40Z80 External Cell Balancing