14 Replies Latest reply on Jul 11, 2016 11:14 PM by user_343349849

    Help with Radiated emmisions

    user_343349849

      I am using a 5LP device in a product that is being tested for FCC  and CE certification. The response is slightly out of limits at 80MHz and I suspect this is the controller. I need to reduce Radiated emission by 2uV at 80MHz.

         

      The controller is being run at 3.3V. 

         

      Are there some relatively easy to implement techniques to lower the RE? (ie. A clock parameter change or something I would turn off)?

         

      The hardware has short traces, plenty of decoupling close by the controller and laid out with large ground plane with lots of vias stitching top and bottom layers. (it is a 2 layer PCB, 1.6m thick with 1oz copper).

         

      My project uses a 1ms timer, SPI, RS485 and a generated 125 kHz Square wave signal from PWM.

         

       

         

      Thanks