Quiescent Operation - Stanford Research Systems SIM918 Operating And Service Manual

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2.8 Quiescent Operation

Note that the operation of the PLL oscillator is completely indepen-
dent of the microprocessor clock.
Follow these steps to operate the SIM918 Precision Current Preampli-
fier in sensitive measurements that can tolerate absolutely no module
clock transitions:
1. Reset the preamplifier (Section 1.5).
2. Set Input to Open.
3. Wait for at least 40 s.
4. Turn autozero o .
5. Select the desired gain.
6. Close the input.
7. Perform the measurement.
After this sequence is complete, the control output of the autozero
circuit holds at a value that initially drives the input o set within its
specification. Without active autozeroing, the input o set may drift
as time progresses, so Steps 1–6 may need to be repeated.
Description of Operation
SIM918 Precision Current Preamplifier