Slew rate enhancement type operational amplifier

Abstract

The invention provides a slew rate enhancement type operational amplifier, which at least comprises a biasing circuit, a first-stage circuit, a second-stage circuit and a drive current regulating circuit, wherein the first-stage circuit is connected to the biasing circuit; the second-stage circuit is respectively connected to the biasing circuit and the first-stage circuit; and the drive current regulating circuit is respectively connected to the biasing circuit, the first-stage circuit and the second-stage circuit and is used for regulating the drive current of the slew rate enhancement type operational amplifier when the slew rate enhancement type operational amplifier drives a load in order to make the drive current of the slew rate enhancement type operational amplifier greater than the bias current to enhance the slew rate of the slew rate enhancement type operational amplifier. In comparison with the class-A operational amplifier in the existing technology, the magnitude of the drive current of the slew rate enhancement type operational amplifier is not decided by the bias current of an output stage, and the drive current can be much larger than the bias current, so that quick charge and discharge under the large capacitance load can be realized without improving the bias current of the output stage, and thus the slew rate is greatly improved.

Description

technical field [0001] The invention relates to the technical field of operational amplifiers, in particular to a slew rate enhanced operational amplifier. Background technique [0002] Operational amplifiers are widely used in the field of analog integrated circuits and are one of the most important modules in digital-analog hybrid circuits. They play a key role in consumer electronics, control and signal conversion systems, and communication systems. For different application fields, the system has different requirements for operational amplifiers. In audio and video signal acquisition, processing and communication system applications, such as LCD display panel driver chips, speaker device drivers, etc., it is usually required that the operational amplifier can drive large loads (such as capacitive loads, resistive loads, etc.) and provide sufficient voltage swing rate and remains stable over large variations in load capacitance. [0003] The slew rate (Slew Rate, SR, or...

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Problems solved by technology

[0006] In view of the above-mentioned shortcoming of prior art, the object of the present invention is to provide a kind of slew rate enhanced operational amplifier, is used to solve the problem that the two-stage transconductance operational amplifier in the prior art improves the slew rate by increasing the bias current of the output stage. cost, the problem of being unable to meet low power consumption requirements, and the problems of crossover distortion of traditional Class B operational amplifiers and the complex structure of traditional Class AB operational amplifiers

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