I have a question about the noise spec in the datasheet of the ADA2200 demodulator:
From the spec for "Shorted Input Noise" of 300uVpp in Table 1 and the output noise plot in Figure 11 it seems that this circuit cannot be used as a synchronous demodulator for discerning changes of approx 30-50uV in the amplitude of an input sine wave. Is this correct?
If this is the case, can you suggest an alternative circuit (e.g. lock-in amplifier), preferably single supply, which would be able to accomplish this task?