TEMPERATURE COMPENSATION BIAS CIRCUIT FOR THE DARLINGTON AMPLIFIER

The present invention relates to a temperature compensation bias circuit, and more particularly, to a temperature compensation bias circuit of a Darlington amplifier to which a temperature compensation transistor is coupled in order to improve a temperature characteristic. The temperature compensation bias circuit includes a first transistor having a base to which a signal is input and an emitter from which a collector-base current Icel is output, a second transistor having a base to which an output signal from the emitter of the first transistor is input and a collector from which a collector-base current Ice2 is output, a temperature compensation transistor having an input connected to the base of the first transistor for temperature compensation of the first and second transistors, wherein the temperature compensation transistor has two transistors connected in series and having bases to which collector signals are respectively input, a first resistor connected to the emitter of the first transistor, for controlling the flow of a current flowing through the first transistor and performing impedance matching, a second resistor connected to the emitter of the second transistor, for protecting the second transistor upon occurrence of overvoltage and performing output impedance matching, and a bias resistor coupled to both ends of the temperature compensation transistor so that a constant bias voltage is applied to the temperature compensation transistor.