Voltage reference source circuit and method for generating voltage reference source

Abstract

The invention relates to an integrated circuit and discloses a voltage reference source circuit and a method for generating a voltage reference source. The method comprises the following steps of: generating a self-adaption nonlinear PTAT (positive temperature coefficient) current through a high-order temperature coefficient compensation circuit; converting the current into a self-adaption nonlinear PTAT voltage and then superposing the voltage with a first-order reference voltage; and generating the reference voltage approximate to zero-temperature coefficient, as the voltage reference source. The self-adaption nonlinear PTAT voltage counteracts the nonlinear negative temperature coefficient in the first-order reference voltage, so the voltage reference source has lower temperature coefficient. In addition, the structure is simple, the compensation branch stability is better and the influence on the initial precision of the voltage reference source is small.

Description

technical field [0001] The present invention relates to integrated circuits, in particular to voltage reference sources in integrated circuits. Background technique [0002] The bandgap voltage reference source is one of the important IP circuits in the design of analog integrated circuits and digital-analog hybrid integrated circuits. Its main function is in the low dropout linear regulator (Low Dropout Regulator, referred to as "LDO"), DC-DC (DC-DC conversion), analog-to-digital converter (Analog Digital Converter, referred to as "ADC") / digital-to-analog conversion Digital Analog Converter (DAC for short) and System on Chip (SoC for short) systems provide stable voltage or current, and are also widely used in precision measuring instruments. [0003] Existing bandgap voltage references are based on the base-emitter voltage difference ΔV of two transistors BE Generate a positive temperature coefficient voltage and the voltage across the transistor base and emitter volta...

AI Technical Summary

Problems solved by technology

Its simulation optimal temperature coefficient is 0.7ppm / °C. Although this structure can realize a reference voltage with a temperature coefficient of sub-1ppm / °C, the stability of its temperature coefficient varies with the process angle, and the high-order positive temperature characteristic current occurs Larger changes, because its ratio is fixed, the non-linear positive temperature characteristic after its superposition will deviate greatly compared with the ideal value, and high-order adaptive temperature compensation cannot be performed, and due to the non-ideal characteristics, will further degrade the temperature coefficient of the reference voltage, and will also affect the accuracy of the output voltage

Images