Switch-type operational amplifier with low power consumption and large oscillation range

Abstract

The invention belongs to the field of micro-electronics, in particular to a switch-type operational amplifier with low power consumption and large oscillation range. The operation amplifier adopts a two-stage operational amplification mode, wherein the second stage is AB-class output; and an electric level shifting circuit is increased between the first stage and the second stage, thereby the polarization state of a second-stage MOS transistor is changed, the low power consumption and large oscillation range of operational amplification can be achieved; in addition, nested Miller compensationis adopted so as to realize the operational amplification stability. The invention can be widely applied in the fields of communication base stations, medical facilities, satellite receiving systems,radars, infrared imaging, digital oscilloscopes, consumer electronics, and the like.

Description

technical field [0001] The invention relates to a novel switching operational amplifier which can be used in switched capacitor circuits, in particular to a switching operational amplifier with low power consumption and large swing. Background technique [0002] As an interface conversion circuit for analog signals and digital signals, analog-to-digital converters are widely used in communication base stations, medical equipment, satellite receiving systems, radar, infrared imaging, digital oscilloscopes, consumer electronics and other fields. Driven by the consumer electronics market, the increasing popularity of battery-powered portable devices requires analog-to-digital converters to achieve high performance while consuming as little power as possible. At the same time, with the continuous development of integrated circuit technology, the power supply voltage is continuously reduced, so low-voltage design is also very important. [0003] The analog-to-digital converter i...

AI Technical Summary

Problems solved by technology

Figure 1(a) is an operational amplifier with a sleeve structure, which has good frequency response characteristics and can achieve high gain at low power consumption, but the operational amplifier with this structure has a small swing and is not suitable for low-voltage operation. Figure 1(b) is an operational amplifier with a folded cascode structure. Compared with the sleeve structure, it can get a larger swing but consumes more power, and it works at a low voltage swing The amplitude is still very small, and it is not suitable for low-voltage operation; Figure 1(c) is a typical two-stage operational amplifier, which can obtain the maximum output swing, but because the two-stage operational amplifier needs frequency compensation to ensure stability, So the second stage of the op amp will consume a lot of power

[0004] It can be seen that there is a certain compromise between the power consumption and the swing of several traditional operational amplifier structures, and it is difficult to achieve a larger swing while lowering the power consumption.

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