I'm using a 120 W DC power supply connected in parallel with ESC and Arduino nano through Vin. However, somehow the Arduino get fried near the CH340 chipenter image description here, i.e. around the big black square chip near the micro usb port on the back of the board, kept getting fried. It's working for a while, until it melted.

This didn't quite make sense, since Arduino Vin can take voltage from 6V to 12V. The ESC also had a maximum current consumption of over 30A, equivalent to 360W. Thus there wasn't an obvious reason for which Arduino ought to get fried at all.

Why CH340 chip getting fried after connecting Arduino to a powerful 12V source?

  • @jsotola It's just standard ESC wiring, and Vin and Vground are in parallel of the power input of ESC with the power souse positive and ground. It's descripted in the post, no tricks. The arduino nano was only used to supply a PWN wave. Commented Jan 6, 2020 at 8:19
  • Precisely which chip is it that gets fried? Is it actually the CH350G or one of the smaller components near it?
    – Majenko
    Commented Jan 6, 2020 at 9:48
  • @Majenko It definitely fried CH300 chip set once, because my computer's usb port got fried once. After that, it's always appear to be near CH300 chip set. However, it wasn't clear weather it's CH300 or the nearby resistor. Commented Jan 6, 2020 at 9:51
  • 2
    It could be that you have a very noisy power supply - one with huge electrical switching spikes in the output.
    – Majenko
    Commented Jan 6, 2020 at 9:52
  • 1
    Maybe the 3-pin voltage regulator is bad, the large chip on the right, and is letting more than 5V thru.
    – CrossRoads
    Commented Jan 6, 2020 at 15:15

1 Answer 1


It's impossible to say for sure what is going on without proper equipment (mostly you need oscilloscope), but I'm pretty sure that due to very high current consumption of the motors, there are voltage spikes at the input of the voltage regulator. If voltage exceeds safe value (15V for most of them), then regulator fails and all the input voltage is now on the output (that's how they fail 99% if the time, not as an open unfortunately, but as a short). Then for some reasons the weakest IC is CH340G which is fried. Try to use destroyed Arduino without ESC, and see what's on the 5V pin. You say that you have currents up to 30A, but PSU is rated for 120W which means it can deliver only 10A at 12V. So at some point PSU falls into protection mode, switches off the output, and after some time tries to switch it on again. Situation with voltage spikes can be very nasty during this period. Also please post your schematic and photo of the actual wiring, this can also give us some clues.

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