Amplifier and method of cancelling distortion by combining hyperbolic tangent and hyperbolic sine transfer functions

摘要

A differential amplifier (10) receives a differential input signal (VIN). The input signal is attenuated by a first attenuator (12) and applied to a tanh amplifier (16). The input signal is also attenuated by a second attenuator (14) and applied to a sinh amplifier (18). The input signals to the tanh amplifier and sinh amplifier are independently attenuated. The transfer functions of the tanh amplifier and the sinh amplifier each have a linear region and a non-linear region. The output of the tanh amplifier and the sinh amplifier are summed (26) so that the non-linear region of the tanh amplifier cancels with the non-linear region of the sinh amplifier. The overall transfer function of the differential amplifier is linear over a wide range of input signal amplitudes by the cancellation of the non-linear regions.