A single-ended input to differential output amplifier performs a predetermined transfer function on an input signal substantially independently of nonlinearities in component values. The input signal and a first reference voltage are coupled to a circuit network, which is coupled to a fully differential...http://www.google.com.au/patents/US5049831?utm_source=gb-gplus-sharePatent US5049831 - Single-ended input to differential output amplifier with integral two-pole filter
