3 Replies Latest reply on Aug 29, 2012 11:15 PM by Steve_McKinney

    USB2.0 signal Integrity


      Any examples of USB high speed signal integrity using hyperlynx?


      I am trying to simulate usb high speed from a MCU. I am not sure what to connect it to. For the time being i tried with LPC1850 mcu and a 90 ohm resistor and 5pf cap to ground from both D+ and D- lines.


      But the problem is when I select high speed USB all I get is a 2 DC waves at the output. One at 2.8v and other at 0v


      If I select full speed pins, I get waveforms as expected (12MHZ).


      The MCU is SAM9G25. Series termination resistors are 22 ohms, TL impedance is 45 ohms.

      FFS attached.