AD8310 - Output Filtering - No Input Scenario

I have been trying to work with the AD8310 to reduce output ripple when in a steady state. It is causing my output comparator to trigger randomly. Before I make significant changes to my output comparator I was hoping to see if I can better setup the AD8310 for this scenario.

In steady state, the system just sees ambient noise. When active, the signal received is 20µs bursts at 1MHz. I see this both in simulation and in hardware.

Input is aggressively filtered by 6th Order+ active filter but the remaining 240µV noise is causing some output ripple that is triggering my comparator. 

I tried adjusting BFIN, OFLT and adjusting input termination.

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  • Hello Eng-Dave,

    Sorry about delayed response. I hope we can still help out if necessary. 

    Looking at the LTspice waveforms, if I'm reading it correct, there is high AM noise at the input, hence high noise at the detector output. Detector characteristics can be modified slightly here and there, but usually it's best to fix the problem at the source. In this application, it might mean larger signal or lower noise into the detector. Perhaps an LNA up front could help.  -Bruce H. 

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  • Hello Eng-Dave,

    Sorry about delayed response. I hope we can still help out if necessary. 

    Looking at the LTspice waveforms, if I'm reading it correct, there is high AM noise at the input, hence high noise at the detector output. Detector characteristics can be modified slightly here and there, but usually it's best to fix the problem at the source. In this application, it might mean larger signal or lower noise into the detector. Perhaps an LNA up front could help.  -Bruce H. 

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