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Digital Filter
12-12
12.11 Digital Filter
The digital filter can use either the fast settling, sinc
2
, or sinc
3
filter, as shown
in Figure 12−4. In addition, the auto mode changes the sinc filter to the best
available option after the input channel or PGA is changed. When switching
to a new channel, it will use the fast settling filter for the next two conversions,
the first of which should be discarded. It will then use the sinc
2
followed by the
sinc
3
filter to improve noise performance. This combines the low-noise advan-
tage of the sinc
3
filter with the quick response of the fast settling time filter. The
frequency response of each filter is shown in Figure 12−5.
Figure 12−4. Filter Step Responses