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Texas Instruments MSC1210 User Manual

Page 148

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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