1 Reply Latest reply on Sep 25, 2019 10:08 PM by BoTa_264741

    Shorting a strong drive PIN



      What would happen on the PSoC 5LP if a pin configured as strong drive is shorted to the opposite level. In other words, what happens if it is shorted to ground while driving high and shorted to power (3.3 V) while driving low? Does the whole chip blow up? Reset? Otherwise, does the pin permanently become unusable? If so, in a high impedance state?


        • 1. Re: Shorting a strong drive PIN


          If shorted in Strong Drive mode, the pin will be blown up. You may check the state of the pin on the PSoC power up - if it shows 5V, it is blown up. (Normal state on startup is LOW).


          I blew up few pins configured in Strong Drive mode by loading high frequency output to a ~0.1u capacitor. All of those pins turn HIGH on the power up. I haven't seen damaged pins which are stayed LOW.


          Do not overdrive pins, the rating is 4mA (source) / 8mA (sink), and for special pins 4mA (source) / 25mA (sink). So for 3-5V, loading resistor should be >1k.