ESP32 custom PCB resets when Wi-Fi starts

[jovelyngentallan02-blip]

Hi everyone,

I’ve designed a custom ESP32 PCB that works normally until Wi-Fi transmission begins, when it occasionally resets with a brownout message. The board uses a 3.3 V regulator rated for 500 mA, with 100 nF and 10 µF decoupling near the module.

This ESP32 PCB design guide recommends careful decoupling and short power-return paths.

Should I use a higher-current regulator, add more bulk capacitance, or investigate the PCB power/ground routing first?

[andypiper]

this feels like a question that would be better directed to a forum or community dedicated to ESP32 and PCB design, rather than a software (MicroPython) discussion community.

[robert-hh]

The ESP32 PCB Design Guide you referenced tells, that the peak current:

"Peak Current: Both (ESP32 and ESP32-S3) can reach 500–700 mA during Wi-Fi transmission, while the ESP32-S3 may experience higher peaks in high-speed USB or camera applications."

So yes, you should both "use a higher-current regulator and add more bulk capacitance". Use low impedance capacitors.

[sosi-deadeye]

Palace the capacitors very close to VDD.

[peterhinch]

As @robert-hh says, ESP32 devices can take pulses of high current when WiFi is running. In addition to the comments re decoupling, ensure that resistance is low in the power and gnd paths. The latter in particular should be designed with broad PCB tracks (or even a ground plane). The aim is to ensure that there is minimal resistive voltage drop: in the gnd tracks there is a risk that voltage drops can affect the logic levels of connected pins.

[projectgus]

This is the third post we've had from a recently joined GitHub account which coincidentally linked to PCBWay content as part of "their question". 😠

1. https://github.com/orgs/micropython/discussions/19360 (also by this account)
2. https://github.com/orgs/micropython/discussions/19331 (another account)

Neither account has any other interactions on GitHub. These questions are not being asked in good faith.