Patent ID: 6982596
Filing Date: 2006-01-03
Classification: H03F,H03G

Abstract:
1. An operational transconductance amplifier comprising: a pair of metal-oxide semiconductor field-effect transistors (MOSFETs) that serves as a differential pair for conducting differential amplification on input voltages; a plurality of constant current sources; a pair of resistors bridge-connected to source terminals of the pair of MOSFETs; a pair of constant voltage MOSFETs that keeps a voltage between source and gate terminals of the MOSFETs as the differential pair constant and keeps transconductance constant; a pair of biasing MOSFETs provided in differential output stages and connected to differential output terminals of the operational transconductance amplifier for conducting biasing on outputs of the differential outputs of the differential pair; and a plurality of capacitors connected between the pair of resistors and for removing a DC offset voltage caused by a characteristic difference between the MOSFETs as the differential pair.