Brownout prevention circuit

[unknow005]

Do not worry! You helped me very much. I will find a different LDO by myself - At least I will learn it by myself.

[mikemoy]

FWIW, i was willing to help, but without knowing certain parameters you cannot effectively choose the proper LDO.
for example. I could choose one that has a input range is 4-5.5v. But if you intended it to be run from a 12v source it would not work.

[EdHayes3]

I know this is a really old post, but wanted to see what the final outcome was.

I was seeing the brownout issues myself today. I historically have had no problems, not sure why I'm seeing it now.

I did recently start working with a battery circuit, so maybe that's related.

I was seeing the brownout error when my ESP32 would start up from deep sleep. The program would check one variable (restart count) and then if it was pass a threshold, turn on WIFI, and retrieve some data. I'm using a M3406 (1.5MHz, 800mA Synchronous Step-Down Converter) from 3.7v battery to 3.3 output. A capacitor seemed to solve the problem for a bit, but was then seeing it again. I have several variations of the same buck IC from different vendors (love these cheep Chinese parts), but none seemed to fix the problem entirely. My solution so far was to add a delay(100) after the chip decides to run WIFI (which is nearly instantly on startup), before it runs the WIFI section. Seems this gives the voltage regulator enough time to ramp up from the low current state to the more demanding state.

[EdHayes3]

My issues continue....

Some minor improvements after adding additional capacitance on the input to the voltage regulator.

Seems that this may be related to breadboarding. My ESP32 worked better when I connected the voltage regulator directly to the ESP32 3.3v input, outside of the breadboard. Still have issues though. The more I wire through the breadboard, or put the ESP module into the breadboard, the more issues I have. The onboard voltage regulator (on the development board) seems to power it just fine.

Just measured 4ohm from one side of the breadboard negative rail to the other. And also the jumper wire had 10 ohm resistance. Something is definitely wrong there.

I'm hoping the PCB I'm making will not have this issue. I know a PCB is copper, and these breadboards are not. I also wont have to deal with the other support components on the breadboard, or crappy jumper wires.

I've never had issues with power over breadboard. Very odd problem.