BQ76952: BQ76952+BQ34Z100 connection query

Star Xu

Part Number: BQ76952
Other Parts Discussed in Thread: BQ34Z100

The customer want to design with BQ7695202 + BQ34Z100. Without writing OTP, considering low power consumption and power-on issues, they want to first supply power to the microcontroller from REG’s 3.3V, then the microcontroller turns on the external LDO power supply and initially sets BQ7695202. CanREG1 and external LDO be connected together?

Waiting for your reply.

Thanks

Star

over 1 year ago

0 Luis H. S. over 1 year ago

TI__Mastermind 42060 points

Hello Star,

Are they planning on turning the REG1 LDO off?

This is not recommended to be doing. Not sure what effect it would have.If doing this however, I'd recommend to have Schottky diodes out of each LDO to ensure that one LDO is not driven by the other.

Best Regards,

Luis Hernandez Salomon

0 Star Xu over 1 year ago in reply to Luis H. S.

TI__Genius 9645 points

Hi Luis

Thanks for your reply.

They want to use REG1's 3.3V to power the microcontroller during power-on transition and turn on the external LDO power supply. The 45mA of REG1 is not large enough, so it needs to rely on an external LDO for operation.

0 Luis H. S. over 1 year ago in reply to Star Xu

TI__Mastermind 42060 points

Hello Star,

Understood. Ensure that the the BQ769x2 LDO is disabled once the external LDO is enabled.

Best Regards,

Luis Hernandez Salomon

Power management

Power management forum

BQ76952: BQ76952+BQ34Z100 connection query