A Hybrid Adjustable Temperature Compensated Bandgap Reference Circuit

Abstract

The invention discloses a mixed adjustment type temperature compensation band-gap reference circuit. An output end of a starting signal of a starting circuit is connected with an input port of a starting signal of a low-voltage band-gap reference circuit; an input end of the starting signal of the starting circuit is connected with a signal output port of the low-voltage band-gap reference circuit; the starting circuit is used for ensuring normal work of the low-voltage band-gap reference circuit; the low-voltage band-gap reference circuit can generate reference voltage with a low temperaturecoefficient, a nonlinear compensation circuit can generate nonlinear compensation current, and temperature curvature compensation circuit can generate temperature curvature compensation current; according to the current superimposing theory, the nonlinear compensation current generated by the nonlinear compensation circuit and the temperature curvature compensation current generated by the temperature curvature compensation circuit are added into the low-voltage band-gap reference circuit, the temperature coefficient of output voltage is greatly reduced, reference voltage with extremely low temperature drift is generated, and the precision of the circuit is improved.

Description

technical field [0001] The invention belongs to the field of integrated circuits, in particular to a CMOS bandgap reference voltage source circuit. Background technique [0002] The CMOS bandgap reference voltage source is one of the important components of the integrated circuit. It provides a reference voltage for other unit circuits in the entire chip, and its performance will directly affect the performance characteristics of other modules and the entire system. [0003] See figure 1 , figure 1 A schematic diagram of the circuit structure of a traditional first-order low-voltage reference voltage source is given. The low-voltage reference voltage source consists of two PNP transistors Q1, Q2, where the emitter area of ​​Q2 is N times that of Q1, three PMOS transistors PM1, PM2, PM3, three of which have the same size, and four resistors R1, R2, R3, R4, wherein the value of R2 is equal to R3, constituted with the operational amplifier OPA. So the current in transistor ...

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Problems solved by technology

[0010] Due to the emitter-base voltage V of the transistor EB The temperature coefficient is not completely negative, and its temperature coefficient also includes higher-order items such as second-order, third-order, and fourth-order, and V T is positively related to temperature and only compensates for the V EB The first-order term of the first-order term leads to a higher temperature coefficient of the output reference voltage, which limits the application of the first-order low-voltage reference voltage circuit in high-precision analog circuits and digital-analog hybrid circuits.

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