Low power consumption high slew rate high gain bandwidth product fully differential operational amplifier

Abstract

The invention discloses a low power consumption high slew rate high gain bandwidth product fully differential operational amplifier. An operational amplifier circuit adopts an input stage current extraction structure and partially extracts currents inside a load pipe through an active current mirror to reduce the effective resistance of the operational amplifier; slew rate enhancing circuits are in parallel connection with bilateral sides of a main operational amplifier to enhance the slew rate of output signals; an output stage applies a Class-AB output structure. According to the low power consumption high slew rate high gain bandwidth product fully differential operational amplifier, the current mirror is connected to an input end load pipe in a parallel mode, the effect of transconductance reduction is achieved due to adjustment of the breadth length ratio of the current mirror, and accordingly the integral circuit keeps the gain bandwidth product and satisfies the integral modulator required level under the condition that the power consumption is reduced and a feedforward structure is connected to the operational amplifier in a parallel mode to inject compensating current for the load to increase the slew rate of the output signals when the operational amplifier is in a working state and transient state power consumption is not consumed excessively.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and in particular relates to a fully differential operational amplifier with low power consumption, high slew rate and high gain-bandwidth product. Background technique [0002] Now all kinds of portable electronic devices are going to millions of households and various industrial applications. Data converters are increasingly in demand as the interface between analog and digital signals. The delta-sigma modulator can achieve unique high precision and has a wide range of applications. In the delta-sigma modulator, the design of the operational amplifier in the integrator is very important, especially the operational amplifier in the front stage, the noise generated by it contributes the most to the total output noise of the modulator. [0003] The op amp is used in a delta-sigma modulator and works as a first-stage integrator. The finite DC gain of the operational amplifier ...

AI Technical Summary

Problems solved by technology

The single-stage operational amplifier has the simplest structure, but it must have a large tail current to achieve high gain and high slew rate. It cannot provide high gain and high slew rate under low power consumption, so few people use it.

Two-stage Miller-compensated operational amplifiers are commonly used, with relatively simple design, high gain, and sufficient phase margin. However, their stability requires large tail current and output stage current, which will increase power consumption; once required Very high output slew rate, then the required current will only be greater

Does not qualify as a delta-sigma modulator at this point

Images