DIFFERENTIAL AMPLIFIER

PROBLEM TO BE SOLVED: To reduce non-linear amplifying errors caused by the temperature difference of a transistor, over a wide range of the frequency. SOLUTION: A differential amplifier has transistors Q1 and Q2 buffering an input signal; a voltage generation circuit generating a voltage drop dependent on a collector current on the side of the collector terminal of the transistors Q1 and Q2; an emitter-follower circuit buffering outputs of the transistors Q1 and Q2; a first differential amplifying circuit cross-connected to the transistors Q1 and Q2 and driven by the emitter-follower circuit; a second differential amplifying circuit driven by the emitter-follower circuit; transistors Q9 and Q10 provided between the transistors Q1, Q2 and the first differential amplifying circuit; transistors Q11 and Q12 provided on the output of the second differential amplifying circuit; and a bias circuit for outputting to the transistors Q9-Q12 a bias voltage which equalizes the collector-emitter voltage of the transistors Q1, Q2 and the first and the second differential amplifying circuits. COPYRIGHT: (C)2010,JPO&INPIT