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AMC1200: AMC1200 design review

Part Number: AMC1200
Other Parts Discussed in Thread: CC1350, DRV8872, , TLV6001

Hi E2E,

Our customer is using DRV8872 motor driver to run DC motors, and wanted to take current logs using Rsense resistor, and for that, they have decided to use an isolation amplifier. The customer would like to know how to feed the output of AMC1200 in CC1350, should they use two GPIOs to feed the output of AMC1200 to CC1350?

Please also help to review their layout and schematic if it is ok for current sensing.

Schematic and Layout.zip


Regards,
Carlo

  • Hi Carlo,

    The CC1350 has an ADC on board right?  Use the analog inputs to connect in the AMC1200.  Your schematic looks a bit off, you might consider using a differential to single ended stage ahead of the CC1350 instead of using the cap you have - not sure if the schematic is complete yet, some connections seem to be missing.  Anyway, you can find an example circuit here: https://www.ti.com/lit/pdf/sbaa229

    You would also need to ensure the output of the differential to single ended stage matches the ADC input range.

  • Hello Tom,

    Our customer have decided to use TLV6001 for single - ended output, which will be fed to the MCU ADC (12-bit). Attached is the schematics using the suggestion from datasheet, can you please help to validate it? It is use for current sensing in DRV8872, some resistor still has no values since the customer will need to calculate it properly.

    Regards,
    Carlo

     

  • Hi Carlo,

    You can add another 1uF cap with the zener supply to the AMC1200.  On the TLA6001, you need biasing on the IN+, please review the app note I mentioned earlier.