3 Replies Latest reply on Apr 1, 2019 11:01 PM by MrMa_286121

    PSOC-5 ADC hanging

    MrMa_286121

      Hi

      I am using a PSOC-5 chip to drive 8 channel buck converter. This is a continuation of an older product that was a 5 channel buck converter controlled by PSOC-4.

      (There are high frequency switched inductors on board)

       

      The problem is that the ADC starts behaving abruptly and gives results greater than 65000. This has been confirmed using the SWD monitor. The entire control loop freezes because of incorrect ADC readout and the LED driver stops working. (The MCU is still running).

      As soon as someone touches the ADC input pin by hand, the ADC magically starts functioning normally and continues to do so. It only hangs randomly during power-on. If it survives the power-on stage, it works ok. But if it hangs during power-on, then someone needs to touch the ADC pin to get it working.

      The input pin is buffered by an external opamp and the voltage is well within range.

       

      Someone please share your experience as to why the ADC will start reading out abnormally high value and get OK when someone touches it.

       

      Thanks