DRV8316: about VSO(off)

Hi ACGUY,

You are correct, the Vso(off) max and min are going to be dependent on the Ioffset value for a particular device. Although ideally the output of the CSAs at 0A would be Vref/2, there is some offset that occurs, and this is taken into consideration by the Ioffset variation as well as the Vdrift coefficient. The Vdrift coefficient looks at how there can be current offset changes across temperature, which will translate into a voltage offset variation based on the gain setting that is used. It is helpful to do a calibration of the CSAs to help account for the Ioffset by measuring the SOx output voltages at 0 current to determine what the offset voltage is. That allows you to compensate accordingly in the code. There will be variations in the offset drift across temperature, but doing an initial calibration will help account for some of the offset drift. The reason there is a max and min Vso is because some devices will tend to have an offset drift voltage above Vref/2, and some devices may have an offset drift voltage below Vref/2.

Regards,

Anthony Lodi