4 Replies Latest reply on Feb 13, 2020 1:36 AM by YoIs_1298666

    [PSOC 4000S] IMO best trimming performance?

    frprc_1262176

      Hi guys,

      in my application I need to trim IMO with WCO. The MCU used is CY8C4024AZI-S413.

       

      In Creator IDE (4.2), IMO accuracy steps down from +/-2% (without WCO) to +/-0.2% (with WCO).

       

      The +/-0.2% is obtained using the default WCO accuracy value (150 PPM).

       

      Trying to lower it to (for example) 10 PPM I expected to see the IMO accuracy becoming lower but this was not the case.

       

      Reading PSOC 4000S TRM, I read:

      1.2 System-Wide resources / 1.5.1 Clocking System

      "The WCO is a 32-kHz watch crystal oscillator. It is used to dynamically trim the IMO to an accuracy of ±1 percent to enable precision timing applications."

       

      So this differs from what Creator IDE says.

       

      Does changing WCO accuracy effectively impact final IMO accuracy? To what extent?

       

      What is the best IMO accuracy? The TRM seems to not report this info.

       

      Regards,

      FP