BALANCED DIFFERENTIAL AMPLIFIER AND BALANCED OPERATIONAL AMPLIFIER

摘要

PPROBLEM TO BE SOLVED: To provide a balanced differential amplifier in which a complete balanced differential output signal can be obtained, an in-phase signal removal ratio is enlarged and in addition, a differential gain is increased. PSOLUTION: In the balanced differential amplifier 10, an input signal is inputted to respective input terminals Vinp, Vinm, the input signal is differentially amplified and a balanced differential output signal produced by the differential amplification is outputted from respective balanced differential output terminals Voutp, Voutm. A pair of differential input transistors Q1, Q2 include a transconductance function for converting a differential input voltage applied to the respective input terminals Vinp, Vinm into a differential current, and drain currents I1, I2 of the respective transistors Q1, Q2 become the differential currents. The differential currents are turned by respective current mirror circuits 13-16 to be supplied to respective current mirror circuits 11, 12. Each of the current mirror circuits 11, 12 then functions as an active load of each of the transistors Q1, Q2. PCOPYRIGHT: (C)2006,JPO&NCIPI