Unable to get 3.3V using Buck 2 in npm1300

[Sourabh Shetty]

Hi,

We have designed a custom board for npm1300 and nrf52832(MS50SFA2 module). We would like to drive the VCC of the BLE module using buck2 but we are only getting 1.8V at the output.

Vset2 is set to 470K to get 3.3V during startup and we are setting 3.3V using software(modified npm1300 one button example). I am attaching the schematic for your reference. 

Please help us resolve this and is the any code that uses buck2 that we could refer apart from npm1300_ek and npm1300_one_button example

Regards,

Sourabh

[Andy Sinclair]

Hi.

Are you able to confirm if this is a software or hardware issue please?

If you powerup the board using VSET to set the voltage (SoC erased or held in reset), do you see 3.3V on the output?

Thanks
Andy

[Sourabh Shetty]

Hi Andy,

I am getting 0.500 V during startup , I am not sure what is causing this issue. I can share the entire schematic in private ticket for review

[dacr]

Hi Sourabh, can you please also share what you measure on VSYS during startup?

[helsing]

Hi Sourab,

Sure, please create a private ticket if you would like us to review the schematic. We can also review your layout.

[Sourabh Shetty]

I am creating a private ticket and sharing all the details asked above.

Thanks