BQ40Z80: It is required that the discharge MOSFET is turned off during charging. Can this be achieved?

jmyang

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQ34Z100

Hi TI experts,

My customer asked to use bq40z80 to design a 7s1p vacuum cleaner battery, charging and discharging port split. It is required that the discharge MOSFET is turned off during charging. Can this be achieved?

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105590 points

Hello,

You can have separate paths for charge/discharge, there is a bit you can set for parallel FET operation.

In the TRM: 12.1 Parallel Protection FET

Sincerely,

Wyatt Keller

0 jmyang over 4 years ago in reply to Wyatt Keller

Expert 1186 points

Hi Wyatt,

Can I realize that the discharge FET is always off while charging？

Can you tell me how to implement this function?

Thanks.

0 Wyatt Keller over 4 years ago in reply to jmyang

TI__Guru** 105590 points

Hello,

This is the operation of that bit:

In a parallel-circuit configuration, if the CHG FET is off and the DSG FET is on, then the CHG FET is not turned on if discharge current is detected. If FETs are configured in parallel, select FET Options[PARALLEL_FETS] = 1.

You would implement the function but turning the PARALLEL_FETS bit to 1.

Sincerely,

Wyatt Keller

0 Wyatt Keller over 4 years ago in reply to jmyang

TI__Guru** 105590 points

Hello,

If this bit does not accomplish your needs you may need to consider using a MCU along with monitor and gauge (like bq34z100) to do the control.

This configuration can be complicated: e2e.ti.com/.../852113

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ40Z80: It is required that the discharge MOSFET is turned off during charging. Can this be achieved?