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Maximum voltage on PIC I/O line

Discussion in 'Microcontrollers, Programming and IoT' started by Rajinder, May 30, 2018.

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  1. Rajinder


    Jan 30, 2016
    Hi all
    I wanted to ask what is the maximum negative and positive voltage i can apply to the PIC I/O line when configured as an input.
    I think it is VDD + 0.3V and VSS-0.3V

    The PIC has input protection diodes. So my question is can i go beyond these limits? Say i had 3.6V and -0.6V. Would the diodes not conduct and prevent damage to the PIC. I presume that there will also be a current limit of the diode that i cant exceed? I am using a PIC16F1938.

    Thanks in advance
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    Nov 17, 2011
    They will conduct and forward energy from the I/O pin to teh supply rail of the PIC with possibly desastrous side effects for the PIC.
    The datasheet specifies a clamp current of 20 mA for this case. As long as your input current is limited to 20 mA or less, a slight overvoltage on the input pin will be tolerated by the chip.

    Have a look at this thread.
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