Multi-tube Combination Curvature Compensation Low Voltage Bandgap Reference Source

Abstract

The invention belongs to the technical field of analog integrated circuits and is characterized by providing a new method for carrying out curvature compensation on a bandgap voltage reference, namely a multi-transistor combination technology. The technology is characterized in that n pairs of compensating current branches are added on the basis of the existing first-order bandgap voltage reference, wherein n can vary along with difference of the process conditions; and each pair of compensating current branches is composed of a sinking current branch with positive channel metal oxide semiconductor (PMOS) transistors as the core and a sourcing current branch with negative channel metal oxide semiconductor (NMOS) transistors as the core. The technology has the following beneficial effects: curvature compensation is carried out on the output voltage reference in the whole temperature range and (2n+1) region extreme points are generated, thus limiting the amplitude of the temperature variation curve of the output voltage reference to ensure the curve to be gentler; therefore, the temperature characteristic of the bandgap voltage reference in the invention is substantially improved compared with the temperature characteristic of the common first-order compensation voltage reference; and the bandgap voltage reference has strong process adaptability, the operating temperature range of the reference is widened, the design difficulty is reduced and the technology can be applied at low power supply voltage.

Description

technical field [0001] The multi-tube combined curvature compensation low-voltage bandgap reference source belongs to the technical field of analog integrated circuits, and is applied to occasions requiring high precision of reference voltages. The proposed circuit is a class of bandgap voltage references that can provide a wide temperature range, low temperature coefficient reference voltage. Background technique [0002] A reference voltage source usually refers to an accurate and stable voltage source used as a voltage reference in a circuit. The purpose of generating a reference is to establish a DC voltage or current with definite temperature characteristics that is independent of the power supply and process. As a core part of analog integrated circuits and digital-analog hybrid integrated circuits, reference voltage sources are widely used. Many integrated circuits and circuit units, such as linear voltage regulators, high-speed memory circuits, analog / digital conve...

AI Technical Summary

Problems solved by technology

[0025] Ordinary first-order temperature compensation bandgap reference source, the temperature coefficient can usually reach 20-30ppm / ℃, and the working temperature range is about 100℃, and in some occasions that require high precision, such as high-resolution DAC, ADC Therefore, high-order temperature compensation must be used to further reduce the temperature coefficient of the bandgap reference source. The current high-order compensation technologies mainly include second-order curvature compensation, exponential curvature compensation, piecewise linear compensation, and curvature compensation using the resistance temperature characteristics of different materials. Correction methods, however, these methods are only in a small temperature range and only compensate for the high temperature section or low temperature section, and do not compensate for the entire temperature section, resulting in a lower temperature range and a higher temperature coefficient, at the same time, traditional methods often do not work well at low supply voltages, and their performance deteriorates as the supply voltage decreases

Moreover, they often have the disadvantages of complex circuit structure, large occupied area, harsh process requirements, and increased manufacturing processes to varying degrees, so their compensation effects are not as good as those of the present invention.

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