LP5907-Q1: There is a power-on overshoot

Hello,

I will be working to answer this thread soon.

Best Regards,

Hannah

Hello,

The schematic shows that EN is tied to Vin, is there a reason for these two pins to be tied together? When EN is tied to VIN, the part could be turning on during dropout. 

Here is an application report showcasing different reasons why overshoot may be occurring in this system and how to avoid overshoot from happening in the future: 

Avoid Start-up Overshoot of LDO (ti.com)

Please let me know if you have any additional questions.

Best Regards,

Hannah

Hi Hannah,

Thanks for your reply!

But if you do not control EN, the manual is recommended to connect the Vin pin directly?

Thanks~

Hi Hannah,

Is there any update？

Rhea Gao said:

But if you do not control EN, the manual is recommended to connect the Vin pin directly?

Hi Rhea,

I am sorry about the late response; I have been out for the holidays. 

I will be looking into this thread again soon.

Best Regards,

Hannah

Hello Rhea,

The EN pin should not be connected to VIN, please see 7.4 Device Functional Modes. 

To see a similar example for the customer's overshoot issue, please see page 2 of Avoid Start-Up Overshoot of LDO.

Please let me know if you have any additional questions.

Best Regards,

Hannah