
174 Analog Circuits Cookbook
on the 2.000 V FSD range, providing a readout of 100 kHz/mV Similar
scaling arrangements can be employed for the other bands, the accuracy of
the resulting readout depending upon the accuracy of the linearisation
employed. This arrangement ignores the effect of centre frequency fine
control
i?2?
which can if desired be taken into account as follows. The outputs
of
A\
and
A%
are combined in a unity gain non-inverting summing amplifier,
the output of which is fed via a 47 k£2 resistor to
A$
as now, and also to the
scaling-cum-offset amplifier.
However, the simplest frequency calibration scheme of all, unlike the