The digital filter receives the modulator output and decimates the data stream. By adjusting the amount of filtering, tradeoffs can be made between resolution and data rate: filter more for higher resolution, filter less for higher data rates. Higher data rates are typically used in ECG applications for implement software pace detection and ac lead-off detection.
The digital filter on each channel consists of a third-order sinc filter. The decimation ratio on the sinc filters can be adjusted by the DR bits in the CONFIG1 register (see the Register Map section for details). This setting is a global setting that affects all channels and, therefore, in a device all channels operate at the same data rate.