A differential termination and attenuator network receives a differential
input signal having a DC common mode voltage. The network circuit
includes input termination resistors coupled in parallel with
corresponding resistive attenuator circuits. A monitoring circuit coupled
to input nodes of the network generates an output signal representative
of the combination of a DC common mode voltage on the input nodes and an
applied termination voltage. A control circuit receives the output signal
from the monitoring circuit and the applied termination voltage and
generates a scaled termination voltage and a scaled compensation voltage
and drive currents. The scaled termination and compensation voltages and
drive currents provide DC currents through the input termination
resistances and the attenuators for nulling DC currents at the network
input nodes and provides a DC common mode voltage output from the
attenuators for optimizing the dynamic range of a differential
measurement amplifier.