Linear temperature coefficient compensated bandgap voltage reference circuit

Abstract

The invention provides a linear temperature coefficient compensated bandgap voltage reference circuit which comprises a MOSFET (metal-oxide-semiconductor field effect transistor) threshold voltage extraction module, a positive-temperature coefficient voltage extraction module and a weight adding module. The MOSFET threshold voltage extraction module is used for extracting threshold voltage with linear negative temperature characteristics, the positive-temperature coefficient voltage extraction module is used for extracting positive-temperature coefficient voltage with linear positive-temperature characteristics, and the weight adding module is used for performing weight adding on the threshold voltage and the positive-temperature coefficient voltage to acquire reference voltage of zero-temperature coefficient. The bandage voltage reference circuit is compensated through a linear temperature coefficient compensation method, the threshold voltage in negative linear relationship with the temperature is generated through the circuit design of the MOSFET threshold voltage extraction module, positive-temperature coefficient voltage in positive linear relationship with the temperature is generated through the positive-temperature coefficient voltage extraction module, the positive-temperature coefficient voltage and the negative-temperature coefficient voltage which are adverse are subjected to weight adding to acquire the reference voltage of the zero-temperature coefficient, and ultra-low temperature coefficient of the bandgap voltage reference circuit.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a bandgap voltage reference circuit with linear temperature coefficient compensation. Background technique [0002] The bandgap voltage reference circuit has the advantages of low temperature coefficient, low power supply voltage and compatibility with standard CMOS technology, and is widely used in digital-analog hybrid circuits such as digital-to-analog conversion, analog-to-digital conversion, memory, and switching power supply. The stability of the output voltage of the bandgap voltage reference circuit and the ability to resist noise affect the accuracy of various application systems. With the improvement of the accuracy of the application system, there is an urgent need for a bandgap voltage reference circuit with ultra-low or even zero temperature coefficient. [0003] The temperature compensation methods of traditional bandgap voltage reference circuits includ...

AI Technical Summary

Problems solved by technology

[0004] In the high-order temperature compensation technology, there is an example of using the high-order temperature characteristics of the resistor for temperature compensation. In this example, the temperature coefficient of the reference voltage can be reduced to 5.3 ppm / °C, but there is a resistance mismatch in the actual process. There are also examples of using the voltage difference of bipolar transistors to form a high-order temperature circuit for temperature compensation. Using this method, the temperature coefficient can be reduced to 7.5 ppm / °C, but this method has a resistance loop in the circuit, which affects the reference voltage. accuracy; there are also examples of using voltage and resistance to form high-order temperature compensation. The temperature coefficient of resistance of this method can be reduced to 4ppm / °C, but this structure directly incorporates the current into the current mirror, and there is a limitation in the matching accuracy of the current mirror. question

In short, although the high-order temperature compensation method can reduce the temperature coefficient to below 10ppm / °C, the complexity and power consumption of the circuit will increase exponentially

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