The low input bias current of 1.0 nA max is made possible with the use of Supereta processing in the input stage. The AD620 works well as a preamplifier due to its low input voltage noise of 9 nV/Hz at 1 kHz, 0.28 V p-p in the 0.1 Hz to 10 Hz band, 0.1 pA/Hz input current noise. Also, the AD620 is well suited for multiplexed applications with its settling time of 15 s to 0.01% and its cost is low enough to enable designs with one inamp per channel. 10,000