Bandgap reference voltage source with high order temperature compensation

Abstract

The invention discloses a bandgap reference voltage source with high order temperature compensation. The bandgap reference voltage source with the high order temperature compensation comprises a three-output switching capacitor converter, a first switched capacitor module and a second switched capacitor module, wherein an input voltage VCC is connected to the input terminal of the three-output switching capacitor converter, and the output terminal of the three-output switching capacitor converter respectively outputs three paths of bias voltages VEB1, VEB2 and VEB3; the first path of bias voltage VEB1 is connected to the first input terminal of the first switched capacitor module, and the second path of bias voltage VEB2 is connected to the second input terminal of the first switched capacitor module and the second input terminal of the second switched capacitor module; the third path of bias voltage VEB3 is connected to the third input terminal of the second switched capacitor module, and the output terminal of the first switched capacitor module is connected to the first inlet terminal of the second switched capacitor module; the output terminal of the second switched capacitor module outputs a reference voltage VREF. The bandgap reference voltage source with the high order temperature compensation provided by the invention is based on a switched capacitor structure, thus greatly reducing the complexity of a circuit, realizing the elimination of a high order term and the bandgap reference high temperature compensation, and obtaining a lower temperature coefficient.

Description

technical field [0001] The invention relates to the design fields of analog integrated circuits and bandgap references, in particular to a bandgap reference voltage source with high-order temperature compensation. Background technique [0002] Bandgap reference voltage source is a basic unit module in integrated circuits, widely used in various analog integrated circuit chips, such as LNA, Mixer, ADC, high-precision comparator, voltage regulator, DC / DC converter, etc., as well as digital Mixed-mode integrated circuit chips, such as D-LDO, VCO, PLL, etc. [0003] The traditional bandgap reference voltage source includes bipolar transistors T1, T2, T3, error amplifier A1, integrated MOS transistors MP1, MP2, MP3 and resistors R1, R2, which are obtained by mirroring the branch current of MP1 and making it flow through resistor R2 The temperature-related voltage term is connected in series with T3, and finally an output voltage VREF that is basically temperature-independent is ...

AI Technical Summary

Problems solved by technology

[0004] Although the traditional bandgap reference voltage source can better eliminate the temperature-related primary term through linear combination, its temperature characteristics are still not ideal due to the high-order term in the expression of the base-emitter voltage of the bipolar transistor. Especially for low-voltage output reference sources, the temperature coefficient can reach hundreds of ppm; in addition, because the traditional bandgap reference voltage source structure needs to use operational amplifiers and more resistors, the circuit complexity is high, the supply voltage is high and the layout area is relatively high. larger

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