LP8725: How to use PMIC

Satoshi Okamoto

Part Number: LP8725

Tool/software:

Hi There,

I plan to use the LP8725-A.
I have some questions about the datasheet.

Q1
Please tell me how to handle each signal when it is not in use.
We are not planning to use DCDC in our system.

Best regards
- satoshi

0 Sarah Lao 7 months ago

Hi Satoshi,

Again, the following connections are typical for unused bucks, but this has not been tested:

Primary concerns would be to make sure BUCKs are disabled/masked in I2C so that no power faults stop the device from running.

Best Regards,
Sarah

0 Satoshi Okamoto 7 months ago in reply to Sarah Lao

Hi Sarah,

Thank you for your quick reply.

RESET_N is not planned to be used in this system.
However, you are concerned about its operation.

We plan to set DEFSEL = VIN1 on the LP8725-A.
In this case, BUCK1/BUCK2 will be OFF in Table 4.

In the above case, BUCK1_EN/BUCK2_EN in the GENERAL register are also masked to 0.

Best regards
- satoshi

Sarah (名) セイラ

+1 Sarah Lao 7 months ago in reply to Satoshi Okamoto

Hi Satoshi,

I see, thank you for the clarification that this is DEFSEL = VIN1 on the LP8725-A.

In this case, I do not see any concerns.
Please follow the connections mentioned in my first comment.

Thank you,
Sarah

0 Satoshi Okamoto 7 months ago in reply to Sarah Lao

Hi Sarah,

I think Sarah will help us come up with the optimal design.
Thanks for your valuable advice!

Best regards
- satoshi

Power management forum