BQ24773: How to select switching Mosfet if I need 17A peak current for SYS and 8A and 1.5A average current for SYS and Charging?

Jason Chen53

Prodigy 20 points

Part Number: BQ24773
Other Parts Discussed in Thread: CSD17310Q5A

How to select switching Mosfet if I need 17A peak current for SYS and 8A and 1.5A average current for SYS and Charging?

By the way, it is applied 1.2Mhz for switching and 2.2uH inductor.

over 7 years ago

0 Wang5577 over 7 years ago

TI__Guru 56650 points

Jason,

BQ24773 is hard to support 17A converter operation because it senses the inductor current from the MOFET's Rds_on. With 17A converter, the MOSFET Rds_on could be too small for BQ24773 sensing the inductor current near zero. I would recommend the total low side FET Rds-on higher than 5mohm.

Thanks,
Wang Li

0 Jason Chen53 over 7 years ago in reply to Wang5577

Prodigy 20 points

Hello Wang Li,

Do you recommend CSD17310Q5A for my application according to your reply?

It seems Current, speed and Rds(on) all suitable.

Jason

0 Wang5577 over 7 years ago in reply to Jason Chen53

TI__Guru 56650 points

Jason,

The power dissipation with 17A DC current is very high for CSD17310Q5A. So, please design the converter current below 10A. When 17A peak current is required, the battery can provide 7A supplement current.

Power management

Power management forum

BQ24773: How to select switching Mosfet if I need 17A peak current for SYS and 8A and 1.5A average current for SYS and Charging?