SBAS655F September 2014 – January 2020
PRODUCTION DATA.
In motor control applications, a very fast response time for overcurrent detection is required. The time for fully settling the filter in case of a step-signal at the input of the modulator depends on its order; that is, a sinc3 filter requires three data updates for full settling (with fDATA = fCLK / OSR). Therefore, for overcurrent protection, filter types other than sinc3 can be a better choice; an alternative is the sinc2 filter. Figure 55 compares the settling times of different filter orders.
The delay time of the sinc filter with a continuous signal is half of its settling time.