Self-calibration band-gap reference circuit and band-gap reference voltage self-calibration system and method

Abstract

The present invention provides a self-calibration bandgap reference circuit, a bandgap reference voltage self-calibration system and method, the self-calibration bandgap reference circuit at least includes: a first voltage signal generation branch, a second voltage signal generation branch, a second voltage signal generation branch, an interchangeable switch, and an operational amplifier with adjustable offset. The self-calibration bandgap reference circuit of the present invention adds two interchangeable switches on the basis of the traditional bandgap reference circuit, and increases the offset adjustable function of the operational amplifier, and makes the offset adjustable operational amplifier through the two interchangeable switches The two input terminals of the circuit can input two voltage signals interchangeably, and the bandgap reference voltage can be calibrated by adjusting the offset voltage of the offset-adjustable operational amplifier. The self-calibrating bandgap reference circuit of the present invention has simple structure, can eliminate the offset of most operational amplifiers, and greatly improves the precision of the bandgap reference voltage.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a self-calibrating bandgap reference circuit, a bandgap reference voltage self-calibrating system and method. Background technique [0002] In analog integrated circuits, bandgap (bandgap) reference circuits are widely used because they vary very little with temperature. Traditional bandgap reference circuits such as figure 1 As shown, it includes: operational amplifier OP, resistors R1, R2, R3, transistors Q1, Q2; assuming R3=R2, its ideal output voltage is: [0003] Vbg=Vbe+(kTlnN / q)*R2 / R1, [0004] Wherein, Vbe is the voltage between the base and the emitter of the triode Q1, k is the Boltzmann constant, T is the temperature, q is the unit electric charge, and N is the number ratio of the triode Q2 to Q1. [0005] Due to the limited precision of the bandgap reference circuit and the generation of random errors during production, the operational amplifier OP will...

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Problems solved by technology

[0010] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a self-calibration bandgap reference circuit, a bandgap reference voltage self-calibration system and method, which are used to solve the problem of band gap in the prior art due to the offset of the operational amplifier. The problem of low accuracy of the bandgap reference voltage output by the gap reference circuit

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