TPSM82866A: Vout drops to 0 upon start-up

David Huang

Part Number: TPSM82866A

Hi Team

As shown below, after a short period of rise time, the Vout stops rising and start to drop to 0 at around 552mV.

Is there any reason that might have caused this problem?

The circuit setup is shown as below

Regards

0 Chris Glaser over 3 years ago

Hi David,

Can you add the SW pin to the scope?

How much output cap is present on the output, on other pages of the schematic?

As a first guess, it looks like you are hitting current limit during startup, as explained here: https://www.ti.com/lit/an/slyt669/slyt669.pdf

Thanks,

Chris

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