Hi to all. i am faced over voltage issue on my controller board. how to avoid over voltage protection in controller GPIO, ADC???

 

Hi to all. i am faced over voltage issue on my controller board. how to avoid over voltage protection in controller GPIO, ADC???

Apologies for being a language pedant, but do you wish to implement over-voltage protection, or do you wish to avoid doing so?

 

A classic means of over voltage protection on GPIO lines is a diode clamp circuit. But if the over-voltage includes mains power it becomes more elaborate.

 

A series resistor (e.g. 10kΩ) to limit the current with two Schottky diodes at the input, one to V+ (cathode) and one to ground (anode) is one common way to protect against plus and minus over-voltages.

 

A series resistor (e.g. 10kΩ) to limit the current with two Schottky diodes at the input, one to V+ (cathode) and one to ground (anode) is one common way to protect against plus and minus over-voltages.

The same circuit, but with regular diodes and a 1000 ohm resistor is what I have used in the past and it worked very well.

 

The same circuit, but with regular diodes

I prefer Schottky since they conduct before the input substrate diodes do, minimizing the possibility of excess current there.

 

The input buffer I used was quite durable. And all of our systems with I/O had input buffers.
I think it was first, a 74C00.

 

Hi to all. i am faced over voltage issue on my controller board. how to avoid over voltage protection in controller GPIO, ADC???

Hi, what board are you using? Is it a Raspberry pi 4 or something else?

 

What sort of "overvoltage"??
Overvoltage could be 5 volts o a 3.3 volt input, or or 120 volts AC. The best protection schemes are a bit different. Or it might even be on an output side. With more details we can provide a useful solution, rather than random guesses.