TRANSISTOR AMPLIFIER HAVING FIELD EFFECT TRANSISTORS WITH STABILIZED DRAIN BIAS CURRENT

摘要

TRANSISTOR AMPLIFIER HAVING FIELD EFFECT TRANSISTORS WITH STABILIZED DRAIN BIAS CURRENT A transistor amplifier is comprised of a first differential amplifier for receiving an input signal and a second differential amplifier coupled to the output of the first differential amplifier. An output stage is coupled to the second differential amplifier and is comprised of a pair of complementary field effect transistors connected in pushpull configuration. Each of the field effect transistors has triode-type dynamic characteristics and is adapted to receive both a bias voltage and an amplified signal from the output of the second differential amplifier. Changes in the operating voltage supplied to the field effect transistors are injected into one of the differential amplifiers so as to effect a corresponding change in the bias voltage which is applied to the field effect transistors. This bias voltage change compensates for changes in the operating voltage so as to stabilize the field effect transistor drain currents at a constant value notwithstanding these operating voltage changes. -i-