PUSH-PULL POWER AMPLIFIER

摘要

PURPOSE: A push-pull power amplifier is provided to prevent a fluctuation of a bias voltage according to a variation of a temperature and a deterioration of a device. CONSTITUTION: A push-pull power amplifier comprises an NPN transistor(Q1) and a PNP transistor(Q2). A first digital-to-analog converter(DAC)(100) outputs a voltage(VBP) to the base terminal of the NPN transistor(Q1) according to a bit rate(A) when a select signal is inputted(Cs). A second DAC(102) outputs a current(ICP) according to a bit rate(B) when the select signal(Cs) is inputted. A bias voltage value setting part(104) inputs a predetermined quantization value(N) of 2N quantization values. A collector current value setting part(106) inputs a predetermined quantization value(N) of 2M quantization values. A control part(108) receives the quantization value from the bias voltage value setting part(104), and applies the select signal(Cs) and the bit rate(A) to the first DAC(100). The control part(108) receives the quantization value from the collector current value setting part(104), and applies the select signal(Cs) and the bit rate(B) to the second DAC(102).