HMC911 input and output problems


We are now using a hmc911 evaluation version of your company, and now we encounter such a problem: our single-ended input is AC coupled, power supply is 3.3V, the control amplitude pin is not connected, we have tried 2.0v, 2.4v and so on for the VAC pin, and there is still no signal at the output, and then no signal can be seen at the output end, how should the input be?

  • 0
    •  Analog Employees 
    on Nov 30, 2020 8:47 AM 1 month ago

    CML inputs should have 400mVpp preferably. If DC terminations do not match, AC coupling should be used at the input and output. 

    Please check supply currents and please check EN_bar pin, since it needs to be floated or applied 3.3V for normal operation. 

    For debug purposed, you could apply the same voltage to VDCP and VDCN to check the output.