DIS07050H : CrowPanel 5.0" HMI ESP32 Display - Powering from 3.3V
My panel starts and runs fine from a 3.3V supply connected to the I2C port. My question is how much power is required to keep it stable. Will 3.3V @ 1A be OK or do I need more?
Thanks.
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UPDATE. TLDR - Don't run these boards off an external 3.3V because they will fail.
We have been running these boards to test using an externally provided 3.3V supply, they were fine for a long time but we just had a failure and U1 (3.3v switching regulator) let out the magic smoke.
Checking the schematic reveals that everything runs off the 3.3v, except for the backlight circuit. U1 and the backlight driver should both be powered by VIN (USB or battery). However, when just an external 3.3V is supplied to the board you still get 3V on VIN. This is because U1 conducts backwards (SW to VCC). This 3V is enough to power U4 (backlight driver) and all appears well, but U1 was not designed to work like this, it gets hot and ultimately will fail.
We have now repaired our failed board and modded the others so we can run them safely off just an external 3.3V supply. Happy making everyone.