| 摘要 |
[Problem] To provide an amplification circuit capable of maintaining high input impedance without being influenced by negative feedback gain setting, and capable of reducing noise caused by an input stage transistor. [Solution] A differential signal is inputted to a pair of gates of a differential pair (10), the differential signal generated in a load circuit (20) connected to drains of the differential pair (10) is amplified in a differential amplifier stage (60), and the amplified differential signal is fed back to a pair of sources of the differential pair (10) via a feedback circuit (40). In the pair of gates of the differential pair (10), high input impedance can be maintained without being influenced by a negative feedback gain in the amplification circuit, and an input stage can be amplified by two first transistor (Q1) and second transistor (Q2) of the differential pair (10), thereby making it possible to reduce the number of transistors at the input stage and reduce flicker noise compared to the prior art. |
