Variable Bandwidth Low Offset Operational Amplifier

Abstract

The invention discloses a variable bandwidth low-offset operational amplifier, comprising a fundamental operational amplifier, a bandwidth adjustment circuit, a 3-8 decoder, an offset calibration circuit and a low-power-consumption control switch. The fundamental operational amplifier is connected with the offset calibration circuit, the bandwidth adjustment circuit and the low-power-consumption control switch. The bandwidth adjustment circuit is connected with the low-power-consumption control switch. The offset calibration circuit is connected with the 3-8 decoder. According to the variable bandwidth low-offset operational amplifier, the bandwidth variable operational amplifier can realized through simple design; a low-offset voltage function can be realized in different bandwidth states; and the technical problem that according to an existing process and an existing technology, the low-offset voltage only can be realized by sacrificing an area of a chip is solved.

Description

technical field [0001] The invention relates to an operational amplifier, in particular to an operational amplifier with variable bandwidth and low offset. Background technique [0002] Operational amplifiers are often common units of integrated circuits. It is the use of operational amplifiers that forms operational circuits with various functions. However, due to the limitations of integrated circuit processing technology, the components of operational amplifiers cannot be made completely symmetrical, resulting in distorted circuits. Matching, and eventually become the offset of the operational amplifier, affecting the performance of the circuit. At the same time, the operational amplifier often needs to change the bandwidth for use, such as reducing power consumption, or improving stability when the load changes, and changing the bandwidth to meet the application requirements of different conditions. Bandwidth-adjustable operational amplifiers often cannot make the offse...

AI Technical Summary

Problems solved by technology

Bandwidth-adjustable operational amplifiers often cannot make the offset voltage very small in different bandwidth states. Excessively increasing the input pair tube in small bandwidth applications will cause the operational amplifier to enter the sub-threshold region, and at the same time cause the chip area to be too large. The deviation between chips makes the offset voltage present a Gaussian distribution. Improving the offset voltage in one bandwidth state may lead to an increase in the offset voltage in another bandwidth state.

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