2 Replies Latest reply on Jun 25, 2010 3:43 AM by userc_44814

    Precision Rectifier using PSoC® 3 AN59649 Not work correctly



       I am trying to use precision rectifier shown in AN59649 but in my opinion it not work correctly.


      Negative half of sine doesn't has gain -1.  Positive half sine gain is correct.


      I attach input (CH I, red) and output (CHII, blue) oscillogram.


      Hardware: PSoC3 CY8C3866LTI-030


      Pins: Input_sine - P0.0 (48), outp - P0.5(54), Reference - P0.1(49)


      External Input_sine pin connected to Reference pin via 10k resistor.


      All input and output have DC votage 2.5V (Vdda/2)


      Input signal sin, 200kHz, 3Vpp connected via 100nF capacitor.


      Power supply:






      I check comparator output, it's correct.






      How make correctly working precision rectifier?




      Best Regards,