A high-gain two-stage operational transconductance amplifier with a cross structure

Abstract

The invention discloses a high-gain two-stage operational transconductance amplifier with a cross structure, relates to the technical field of operational transconductance amplifiers, solves the problems of low gain, low output pole frequency and poorer circuit stability of the existing amplifier. the technical scheme includes that the operational transconductance amplifier comprises a two-stage amplifying circuit, a damping factor control module circuit and a biasing circuit for providing bias voltage for a circuit structure, Wherein the first stage of the two-stage amplifying circuit is a PMOS tube differential input amplifying circuit, and the second stage of the two-stage amplifying circuit is a complementary push-pull driving circuit of a common-source gain stage; The damping factor control module circuit is connected with the output end of the PMOS tube differential input amplification circuit; A first capacitor C1 used for forming a Miller compensation path is arranged between the output end and the input end of the complementary push-pull driving circuit of the common-source gain stage, the circuit can be stabilized, and under the condition that the whole circuit is in lowpower consumption, the effects of improving the gain, the common-mode rejection ratio and the power supply rejection ratio of the circuit are achieved.

Description

technical field [0001] The invention relates to the technical field of operational transconductance amplifiers, more specifically, it relates to a cross-structure high-gain two-stage operational transconductance amplifier. Background technique [0002] The operational transconductance amplifier is an integral part of many systems. As an operational amplifier that eliminates the buffer output, the operational transconductance amplifier has a high output impedance and is a voltage / current mode hybrid circuit. Its performance It determines the performance of the entire integrated circuit system and has become a research hotspot in the field of microelectronics. [0003] At present, the existing two-stage operational amplifier structures are generally simple two-stage operational amplifier structures, telescopic cascode structures and folded cascode structures. Among them, the gain of the simple operational amplifier structure is often relatively low, and it is difficult to mee...

AI Technical Summary

Problems solved by technology

Among them, the gain of the simple operational amplifier structure is often relatively low, and it is difficult to meet the practical requirements; while the telescopic and folded structures will increase the number of transistors and increase the complexity of the circuit, and these two structures are designed to increase the output of the circuit. Impedance is the starting point to increase the gain, but too large output resistance will also cause the frequency of the output pole to decrease, reducing the stability of the circuit

Images