National Instruments SCB-68A - Analog Input Highpass Filtering Applications

© National Instruments | 2-31
NI SCB-68A User Manual
Figure 2-29. SCB-68A Circuit Diagram for Single-Ended Analog Input Highpass Filter
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Analog Input Highpass Filtering Applications
One of the most common applications for highpass filters for analog inputs is to use the filter to
do AC coupling. AC coupling can be achieved by creating a highpass filter with a very low
cutoff frequency. This filter allows most dynamic signals through, while it blocks any DC offsets
in the signal. This can be used to increase the resolution with which you can measure a dynamic
signal that is riding on top of an offset, as shown in Figure 2-30.
Figure 2-30. Signal before Passing through Filter
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