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DRV411: compensation coil resistance and inductance problem

Part Number: DRV411

Hi TI engineer,

If I want to drive the compensation coil 250mA current and the voltage between the compensation coil is 4.2Vpp, the compensation coil resistance + the resistance of RSHUNT must be small than 4.2V/250mA=16.8Ω.

Is it right? 

If it is right, it's different for us to measure 500A current, because the coil resistance normally is bigger than 20Ω in 1:2000 conversion ratio.

Gain_3 mode is for compensation coil inductance typically ≥ 50 mH.  Could you tell me what the coil inductance influence?



  • Hello Barry,
    Thanks for considering to use Texas Instruments, we will have a response for your issue on the next business day, which begins on Monday 8 am U.S.A Mountain Time.
  • Hello Barry,

    You are correct but I would not design the system expecting the 250mA output but rather design it with the max current of 250mA.  Typically most units could reach that but for a robust system I would recommend the minimum guaranteed of 210mA.  Also please verify in your system as not all conditions will be exact conditions as our datasheet.

    For 500A you may come to a trade-off with the output current limitations, number of winding, and thickness of winding for resistance.  If you cannot meet the trade off you could consider increasing the output capability like in this TI Design ().