protecting analog input of microcontroller
protecting analog input of microcontroller
(OP)
I have a dual schottky diode connected to my analog input of my microcontroller. Is the only component that can be used to protect the IO pin from voltage spikes or ESD?





RE: protecting analog input of microcontroller
RE: protecting analog input of microcontroller
RE: protecting analog input of microcontroller
When the voltage on the input pin exceeds the zener voltage they "clamp" the pin voltage to the zener voltage. Make sure you size it correctly for current carrying ability if you think there could be the potential for a high-current spike. Otherwise if it is just a signal you would probably be fine with the standard small signal diode package.
RE: protecting analog input of microcontroller
RE: protecting analog input of microcontroller
RE: protecting analog input of microcontroller
RE: protecting analog input of microcontroller
Schottky diodes are much leakier than signal diodes...
Have a look a the spec sheet for your device & compare it with a 1n4148 or whatever.
RE: protecting analog input of microcontroller
I still say u rarely need them in that service. I have never used them in dozens of projects that have lots of handling.
If your analog source originates on your board you absolutely don't need them.
RE: protecting analog input of microcontroller
RE: protecting analog input of microcontroller
And decide;
1) This micro has beafy Schottkys inside. I don't need to add external ones.
2) To cut ANY Schottkys a break I should have some series impedance on that input. Is there some already due to whatever, like a voltage divider, etc. If not, I should add some being careful not to add too much if the signal is rapidly varying or the R-C this protection resistor teamed with the processor's pin capacitance will start causing other problems.
RE: protecting analog input of microcontroller