| 摘要 |
PROBLEM TO BE SOLVED: To provide a multistage amplifier with low power consumption and excellent characteristics.SOLUTION: A multistage amplifier 10 comprises: a first-stage amplifier 11; a second-stage amplifier 12; a final-stage amplifier 13; a bias circuit 31 which supplies current bias to the first-stage amplifier 11; and a bias circuit 32 which supplies current bias to the final-stage amplifier 13. The multistage amplifier further includes an adjusting circuit which adjusts an amount of current flowing through an intermediate node 150 so as to suppress potential variations of the intermediate node 150. In an embodiment 1, the second-stage amplifier 12 plays a role of the adjusting circuit. A self-bias CMOS inverter can be preferably applied to the second-stage amplifier 12. The bias circuit 31 supplies current bias to gates of first-stage amplification transistors Tr1, Tr2, and Tr3 so that the magnitude of bias increases in response to a rise in a circuit temperature.SELECTED DRAWING: Figure 3 |
