Help needed, my switching voltage regulator is not working

[famez]

Hello everyone,

First of all, I want to let you know that I am a total noob, I am telecommunications engineer working for a company that manufactures embedded devices. My background is more related about embedded software / cybersecurity.

So, I wanted to desing my first board, and I tried with RPI PICO (RP2040) following the electric schematics publictly available here: https://datasheets.raspberrypi.com/pico/pico-datasheet.pdf (page 25).

I designed everything and sent it to JLCPCB for manufactoring.

When connecting the PCBA to the USB, it was not recognised by my computer.

I started measuring 3V3 signal with a multimeter and it gave me only 0.5V and I don’t know why. I suppose that the problem is the voltage regulator (because the USB is giving me 5V).

So, I just desoldered the voltage regulator and injected and external 3V3 voltage supply. With this, my PCBA is working as expected (I flashed a simple SW to make a led flash, and it is working).


Can you help me, please? I know that some traces have incorrect angles (more than 90 º). Could it be the problem? Any other good design rules or tips are appreciated.

By the way, no errors in the DRC, only warning about silkscreen, but I didn’t send the silkscreen layer to be manufactured.

Thanks in advance!!

PD: The project is attached in this thread in zip format. It is a Kicad project.

PD2: The voltage regulator is this model: RT6150BGQW (from 5V to 3V3).


Let me know if you need further details.

[xvr]

FB pin should be connected to voltage divider, not directly to output. In this configuration you will get 0.5V on output (not 3.3V)
Also copper area under U2 is too small. It used as heatsink. In your configuration U2 can get very hot (or even shut down on overheat)

[xvr]

PD2: The voltage regulator is this model: RT6150BGQW (from 5V to 3V3).

3.3V model is RT6159B33GQW

[famez]

Thanks for your reply. That was exactly my problem, I tested it manually and seems to work.