55.6.2.3 Droop Compensation

The droop effect introduced by the sinc filter can be compensated in the 0 to 20 kHz by the droop compensation filter (see Figure 55-5). This is a second-order IIR filter which is applied on the signal output by the sinc. The default coefficients of the droop compensation filter are computed to optimize the droop of the sinc filter with the decimated frequency equal to 48 kHz.

This filter compensates the droop of the sinc filter regardless of the OSR value.

If the decimated sampling rate is modified, the frequency response of this filter is scaled proportionally to the new frequency.

This filter can be bypassed by setting the SINBYP bit in the PDMIC DSP Configuration Register 0 (PDMIC_DSPR0).