Input Filter Details - Stanford Research Systems SR124 Operation And Service Manual

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3.3 Input filter details
Table 3.3: Maximum input signals before PSD overload
Sensitivity
High Res. Normal
100 nV
200 nV
500 nV
1 V
2 V
5 V
10 V
20 V
50 V
100 V
200 V
500 V
1 mV
2 mV
5 mV
10 mV
20 mV
50 mV
100 mV
200 mV
500 mV
The input filter is constructed as a state-variable filter with user-
settable cuto frequency f
gain of the input filter is calibrated to be unity. The nominal transfer
functions are shown in the following figures.
Of particular note is that the pass-band portion of the low pass and
high pass filters have a gain of 1 Q far from the resonance. For
most applications requiring low pass or high pass input filtering, it
is e ective to leave Q 1.
Low Noise
100 nV
200 nV
500 nV
100 nV 1 V
200 nV 2 V
500 nV 5 V
1 V 10 V
2 V 20 V
5 V 50 V
10 V 100 V
20 V 200 V
50 V 500 V
100 V 1 mV
200 V 2 mV
500 V 5 mV
1 mV 10 mV
2 mV 20 mV
5 mV 50 mV
10 mV 100 mV
20 mV 200 mV
50 mV 500 mV
100 mV
200 mV
500 mV
and Q-factor. In the SR124, the peak
0
SR124 Analog Lock-In Amplifier
Performance Details
Maximum
input (RMS)
7 V
24 V
63 V
7 V
24 V
63 V
130 V
250 V
650 V
1.3 mV
2.5 mV
6.5 mV
12.5 mV
14 mV
14 mV
129 mV
160 mV
160 mV
1.25 V
1.25 V
1.25 V
1.25 V
1.25 V
1.25 V
1.25 V
1.25 V
1.25 V