QIn AD630 DS, it says AD630 can be used to build up a lock-in amp to pick up
narrow band signal from big noise. I would like to know if the lock-in amp can
work with DC signal, if a low level DC signal buried in the noise, can we use
lock-in amp to pick up it.
AThe AD630 operates synchronously, referring a signal with high noise content to
a known frequency reference. Therefore the dc case would be irrelevant. One can
simply filter noise from dc to detect any dc level present.