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Phase Compensation of Voltage Follower
It is important to separate a useful signal from noise in measuring small
voltage deviations of about 1 m V and lower. This problem is relevant to
eddy-current testing method in non-destructive testing metal constructions,
thermal nondestructive testing, etc. The identification accuracy of a
useful signal directly depends on the common-mode rejection ratio of
subtraction circuit. The paper presents the circuit solutions concerning
the increase in the common-mode rejection ratio using the power tracking
with the phase error compensation of the voltage follower transfer
factor and proposes a schematic circuit diagram of the phase compensated
power tracking. The circuit was proposed for the phase compensated power
tracking. The subtraction of two similar voltages of10 V on the PGA207
instrumentation amplifier could provide a 10 nV resolution at a frequency
band up to 20 kHz.
