About the Output of AD8310


Recently  I designed an eva board of  AD8310, I find when left the input of AD8310 floating,the output is sawtooth wave about 400mVpp .But if there are high frequency signal on the input port,the output noise is about 20mVpp and no sawtooth wave .I don't know why. I need your help.

  • 0
    •  Analog Employees 
    on Dec 26, 2019 9:21 PM over 1 year ago

    AD8310 is a very sensitive RF detector, responding to RF signals as -80 to -90 dBm. 

    You might find low-frequency noise pickup from outside sources could cause this. Things nearby like wall-wart switching power supplies, AM broadcast stations, embedded MCUs, etc. It could be that the printed microstrip input trace is acting like a receive antenna, thereby coupling these outside noise sources into the AD8310 detector. 

    Try a 50 Ohm SMA termination on the input, to see if that helps. If so, a proper shield around the RF detector may be necessary.

  • Hi,Bruce_H.

    Thanks for your reply.

    There is a 50 Ohm termination on the input already.

    According to your suggestion,I will add a shield to do more test.