ULTRA-LOW WORKING VOLTAGE RAIL TO RAIL OPERATIONAL AMPLIFIER AND DIFFERENTIAL INPUT AMPLIFICATION-STAGE CIRCUIT AND OUTPUT-STAGE CIRCUIT THEREOF

摘要

The differential input amplifier circuit 100 includes a voltage unit 10, first and second bulk-drive transistors 20 and 30, first and second mirror current sources 40 and 50, and a differential amplifier unit 60 do. The voltage unit 10 includes first to third voltage output terminals 11, 12 and 13. The first voltage output terminal 11 is connected to the first and second bulk-drive transistors 20 and 30. Respectively, to the first and second bulk-drive transistors, respectively, and converts the first input voltage and the second input voltage into first and second output currents, respectively. The differential amplifier unit 60 individually outputs the first and second adjustment currents under the action of the voltages output to the first to third voltage output terminals 11, 12 and 13. The first and second mirror current sources 40 and 50 supply the first and second predetermined currents I _{OUT +} and I _OUT- to the first output current and the first adjustment current, and the second output current and the second adjustment current, respectively And maintains the transconductance invariance of the differential input amplifier stage circuit 100. Therefore, the output stability is improved. Further, an output stage circuit 200 and an ultra low operating voltage rail-to-rail operational amplifier 300 are additionally provided.