Operational transconductance amplifier applicable to infrared detector circuit

Abstract

The invention discloses an operational transconductance amplifier applicable to an infrared detector circuit. An application environment of the operational transconductance amplifier is a front-end amplification circuit of an infrared reading circuit, which is composed of an input stage, a bias stage and an output stage, wherein the input stage is a push-pull structure connected to a differential inverter, which is composed of two PMOS transistors and two NMOS transistors; relatively high input transconductance can be used for forming relatively high gain and bandwidth; the bias stage is a cascode structure, which is composed of two PMOS transistors and two NMOS transistors, and used for increasing the gain and power supply rejection ratio; the output stage is a cascode current mirror, which is composed of four PMOS transistors and four NMOS transistors; by means of the structure, relatively high output impedance can also be provided while current is output; furthermore, due to the current mirror structure, a common-mode feedback structure can be prevented from being used; and thus, the circuit complexity is reduced. The operational transconductance amplifier disclosed by the invention overcomes the problems of low gain of a five-transistor unit structure, small bandwidth of a folding cascode structure and the like, and satisfies time sequence requirements of an infrared reading post-stage circuit.

Description

Technical field [0001] The invention relates to the field of integrated circuit design, in particular to the design of an operational transconductance amplifier. Background technique [0002] Since the advent of operational transconductance amplifiers, transconductance amplifiers have made greater and greater progress in both manufacturing process and circuit design, and have gradually met the needs of various applications. Transconductance amplifiers such as high gain and high bandwidth have gradually occupied the market, improving efficiency and reducing costs. [0003] At present, the relatively simple operational transconductance amplifier uses a five-tube unit structure, such as figure 1 Shown. The operational transconductance amplifier of the five-tube unit has relatively low power consumption, but its gain is relatively low, and often cannot meet the application requirements. Operational amplifier with folded cascode structure, its structure is as figure 2 As shown, when ...

AI Technical Summary

Problems solved by technology

The operational transconductance amplifier of the five-tube unit has relatively low power consumption, but its gain is relatively low, which often cannot meet the application requirements

An operational amplifier using a folded cascode structure, the structure of which is as follows figure 2 As shown, when the gain requirement is met, the bandwidth is often relatively small, and it cannot meet the specific application

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