A bandgap reference circuit

Abstract

The invention relates to the technology of integrated circuits, in particular to a band-gap reference circuit. The band-gap reference circuit is characterized by comprising a first current reference unit, a second current reference unit, a maximum current selecting circuit and a reference voltage output unit, wherein the output end of the first current reference unit is connected with the first input end of the maximum current selecting circuit, the output end of the second current reference unit is connected with the second input end of the maximum current selecting circuit, the output end of the maximum current selecting circuit is connected with the reference voltage output unit, and the output end of the reference voltage output unit is the output end of the band-gap reference circuit. The band-gap reference circuit has the advantages of being better in temperature coefficient of an output voltage compared with a traditional scheme, and being simple in circuit structure and high in reliability compared with a high-order compensation circuit. The band-gap reference circuit is applicable to voltage reference circuits.

Description

technical field [0001] The invention relates to integrated circuit technology, in particular to a bandgap reference circuit. Background technique [0002] As a basic circuit unit, reference voltage sources are widely used in power regulators, digital-to-analog and analog-to-digital converters, data acquisition systems, and various measurement equipment. With the development of integrated circuit technology, the performance requirements of chips are getting higher and higher, and many chips need precise and stable reference voltage sources. [0003] Traditional voltage reference sources such as figure 1 As shown, the principle of the circuit to generate the reference voltage is as follows: Use current mirrors M1, M2 and current mirrors M3, M4 to make the collector voltages of transistors Qa and Qb equal, that is, the voltages at points A and B are equal, and Qa, Qb and Ra forms a loop, and the voltage drop above Ra is the difference between the base and emitter voltages of ...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, based on the first-order linear compensation reference circuit, the accuracy of the reference voltage can be improved by additionally adding some high-order compensation circuits such as the second-order compensation circuit and the exponential compensation circuit, but adding the compensation circuit will increase the design difficulty and Circuit complexity is not conducive to system stability

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