7 Replies Latest reply on Sep 21, 2015 10:33 AM by user_14586677

    Op Amp in Comparator mode doesn't work

    elias.hernndez

      Hi guys, I don't know what's wrong, but I've got a project in which I use an Opamp v1.10 to make an active filter with external components, and it works like a charm when I check it with an oscilloscope (I use three analog pins to route the V+, V- and Vout signals outside and inside the psoc).

         

      But if I try the same component with the same analog pins to make an operational amplifier in comparator mode, the oscilloscope graph never change. Instead of showing a digital like signal (high voltage signal when V+ > V-, and low voltage signal when V+ < V-) it only shows a noisy and unchanged level signal, whatever values I plug in to the V+ and V- pins, there's no variation in the noise.

         

      I've also tried the Low Power Comparator v2.10, but again I can't obtain anything else that a noisy signal that doesn't change it's level whatever voltages I plug in the V+ and V- pins.

         

      Thus, I ask here because I want to know if PSoC have some kind of problem, or special configuration  needed in order to use the low power comparator or the internal op amp in comparator mode.

         

       

         

      PD: I haven't uploaded the project because analog pins and op amp was working flawlessly in active filter mode with external components, so I think my code is fine with the opamp_Start() function, and in order to use the op amp in comparator mode it doesn't require anymore than remove the external components used before, and just plug in two different DC voltage signals in V+ and V- that I can vary, and check the Vout with the oscilloscope.