DRV411: How to implement demagnetization function for DRV411

Sato,

The DRV411 does not have a demagnetization function.  There are two reasons for it but if required one can implement it with external circuitry.  

1. The DRV411 controls a hall sensor which is less sensitive than that of a flux gate.
2. The core air gap is typically larger and is less likely to saturate and become magnetized.

If you still require the demagnetization you will need to supply an alternating current that decays with time.  This can be done with amplitude reduction or duty cycle reduction.  See image attached.  The start of the current amplitude or time must saturate the core and decay to a point where it no longer does.  The value of the current will be based on the material and air gap size and number of windings on the core.

Sato,

I have a circuit I used but at the time I verified this the DRV8837C was the cheapest driver that would work.  Below are two example circuits.  The switches need to be verified for the amount of current required and the input to the digital of the DRV8837C where given by a controller.  All components need to be verified for the current and voltages required.