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I can not work with HMC799LPE Eval board

Question asked by imam.zaman on Jul 29, 2018
Latest reply on Jul 30, 2018 by Gauzz

I am trying to use HMC799LP3E. I have the evaluation board as well. However, when I connect RFin port to a photodiode it does not work. Without TIA, When I see photodiode output in an oscilloscope(50ohm), I see a 47mv amplitude signal. When I add TIA, I see almost nothing in an oscilloscope, just a spike and some ringing with it 

 

In the datasheet, it is mentioned that Input bias voltage 2.1V. How do I make sure that the input bias voltage is 2.1V. The photodiode is giving current and I am connecting the photodiode directly to TIA. I tried to use BIAS Tee to add 2.1V to the photodiode output but apparently, bias tee does not work with a current. What am I doing wrong here?

 

NB. I am a newbie in this field.

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