Chapter 4
Theory of Operation
4-8
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The isolated amplifiers fulfill two purposes on the SCXI-1120/D module.
They convert a small signal riding on a high common-mode voltage into a
single-ended signal with respect to the SCXI-1120/D chassis ground. With
this conversion, the input analog signal can be extracted from a high
common-mode voltage or noise before being sampled and converted by the
DAQ device. The isolated amplifier also amplifies and conditions an input
signal, which results in an increase in measurement resolution and
accuracy.
After isolation, further filtering is available to increase the noise immunity
of the amplifier channel. It is important to note that the overall amplifier
bandwidth is determined by both filtering stages, so to achieve the required
bandwidth, both filtering sections should be set the same, as indicated in
Chapter 2,
