AD8476 - Reducing the gain

Document created by analog-archivist Employee on Feb 23, 2016
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Can I reduce the gain of the AD8476 by placing equal resistors in series with
the inputs?


It is not recommended.
The RF/RG ratio on the positive and negative side are trimmed to be very close
to 1, causing gain and common-mode rejection errors to be very small. External
resistors are placed in series with RG, but because of the absolute resistor
tolerance of ±20%, RG on the positive side can be very different from RG on the
negative side, meaning even well- matched external resistors can greatly
unbalance the RF/RG resistor ratios and significantly increase gain and
common-mode rejection errors.