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TIDM-1000: AMC1301

Steven MacDonald1
Prodigy 200 points
Part Number: TIDM-1000
Other Parts Discussed in Thread: AMC1311, AMC1301, OPA320

Good Afternoon,

I am having trouble measuring the pfc bus voltage in our circuit which was derived from the TIDM-1000, probably due to switching noise in the pdc, dcdc and/or inverter circuits.

I am thinking of replacing the AMC1301 with the AMC1311. Is this a good idea.

Thanks

Steve

  • 0
    TI__Guru 56532 points

    Hi Steve,

    I see that in TIDM-1000 there is no anti-aliasing filter. Adding one may help clean up some of the high frequency noise that you must be seeing as it could be aliasing back into the sample band of the delta-sigma modulator. 

    The AMC1311 is ideal for DC voltage sensing, with a 0-2V input range and fixed gain of 1. The AMC1301 is ideal for AC current sensing, with a +/-250mV input range and fixed gain of 8.2. 

    If replacing AMC1301 with AMC1311, I would recommend removing R3' (R56, R71, R83) in this schematic : https://www.ti.com/lit/df/tidrp45a/tidrp45a.pdf

    and adding a common-mode anti-aliasing filter (50ohm, 50ohm, 10nf).

    You may also want to try installing the capacitors on the output of the AMC1301 and feedback of the differential to single-ended opamp, OPA320 - as they could help filter out the high frequency noise as well. 

  • 0 in reply to Alexander Smith
    Prodigy 200 points

    Hi Alex,

    Thanks for the prompt response!

    I will try some filter caps while waiting for the AMC1311 to arrive

    Thanks

    Steve