VXO7805-1000 DC to DC converter supplies 5V.

When the circuit is attached via USB, there is a voltage drop to 4.5V on the 5V pin of the ESP32 (DevKitC-32D and pinout).

I tried adding a 10uF capacitor between ground and EN (RST) as mentioned here. I then tried 330 uF. No luck.

This seems to be what I'm encountering:

https://www.reddit.com/r/WLED/comments/zkbnj9
Is a potential solution using a different DC-DC regulator? I will be eventually using an MIC29310-5.0WT or LD1085V50. I asked another employee to order the first one (same pinout) and they said I should rig up a second regulator VXO7803-1000 to some 3v3 pin. Then they said something about how if that works, it would be unfortunate to have to use the VXO7805 and VXO7803...

I don't understand them. Is there something going on where a regulator with a lower input voltage, such as the MIC29310-5.0WT (2.3-16V) would probably not solve the issue? From that reddit post above, I thought that's what Jem_Spenser was saying. Maybe I do not understand what they meant.

 

If the voltage of a power supply is dropping, when you add a load, it means you are drawing more current than it can supply.

Are you placing an LED across a 5V supply without a resistor? That would do it.

 

You say " VXO7805-1000 DC to DC converter supplies 5V " and you say "Voltage drops to 4.5V when load is 2A"
Since the VXO7805 spec sheet says its a 1A supply (max) and you are drawing 2A (2x max rating), yes the output will drop and nothing will help other than replacing VXO7805....

 

You say " VXO7805-1000 DC to DC converter supplies 5V " and you say "Voltage drops to 4.5V when load is 2A"

Where do you see that? I have reread the post and no current is mentioned that I see.

 

You say " eventually using an MIC29310-5.0WT or LD1085V50 "
Yes these get you to 3A supply (you seem to require 2A), BUT using LDO regulators for high currents with high voltage inputs
give a real heat/power headache. The V(dropout) is 1.3V, therefore you need at least 6.3V on the input side. At 2A and 1.3V drop across LDO you will need to dissipate 2.6W of heat/power requiring heatsink and fan. If your input was 9V you would be at 5.2W of heat. What you need is a DC-DC converter that can handle our 2A load requirement.

 

Where do you see that? I have reread the post and no current is mentioned that I see.

 

That is a quoted post from some other forum, not a description of the problem by the TS.

 

Really? He stated "This seems to be what I'm encountering" and then posts quote. Seems like he IS describing his problem by analogy to the quote. Why don't we wait and hear from the TS.

 

If the system works when establishing the load after the micro boots, then maybe a coded delay might solve the problem.