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

摘要

A differential amplifier (10) receives a differential input signal (V. sub.IN). The input signal is attenuated by a first attenuator (12) and applied to a tan h amplifier (16). The input signal is also attenuated by a second attenuator (14) and applied to a sin h amplifier (18). The input signals to the tan h amplifier and sin h amplifier are independently attenuated. The transfer functions of the tan h amplifier and the sin h amplifier each have a linear region and a non-linear region. The output of the tan h amplifier and the sin h amplifier are summed (26) so that the non-linear region of the tan h amplifier cancels with the non-linear region of the sin h 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.