Low-temperature drift detuning self-calibration operational amplifier circuit and design method thereof

Abstract

The invention relates to a low-temperature drift detuning self-calibration operational amplifier circuit and a design method of the low-temperature drift detuning self-calibration operational amplifier circuit. The low-temperature drift detuning self-calibration operational amplifier circuit comprises two gain units, a biased module, three capacitors, a current source, six switches, four P-type metal oxide semiconductor (MOS) pipes and five N-type MOS pipes, wherein each gain unit comprises a capacitor, two resistors, a switch, ten P-type MOS pipes and four N-type MOS pipes. A folded cascade structure is adopted to be used as a gain stage of an amplifier so that high voltage gain and a high power supply rejection ratio can be obtained. Due to the fact that the MOS capacitor is adopted to store, operate and amplify detuning information caused by technology variation, and the detuning information is successively and automatically calibrated when a closed loop is used, low direct current detuning is achieved. A lower temperature coefficient is achieved by adoption of a temperature compensation technology. A high drive capability is obtained by adoption of push-pull output of an AB class.

Description

technical field [0001] The invention belongs to the field of power supplies, in particular to a low-temperature drift offset self-calibration operational amplifier circuit and a design method, which are mainly used in DC / DC converters, AC / DC converters, LED drivers, class D power amplifiers, and high-precision current limiting switch, battery protection chip, etc. Background technique [0002] In recent years, the consumer electronics market has continued to expand, and the field of integrated circuit power supplies has also expanded rapidly. With the increasingly high performance requirements of products, the performance requirements of power supply ICs have also become more and more stringent. As the core module of all power supply products, the reference voltage source has been plagued by insufficient driving ability. Using an operational amplifier as the driving stage can improve the driving ability of the reference voltage source. However, the offset of the operational ...

AI Technical Summary

Problems solved by technology

As the core module of all power supply products, the reference voltage source has been plagued by insufficient driving ability. Using an operational amplifier as the driving stage can improve the driving ability of the reference voltage source. However, the offset of the operational amplifier itself brings DC deviation to the system, which greatly affects the system performance

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