Voltage regulator

Abstract

The invention provides a voltage regulator which adopts a reference voltage source capable of automatically eliminating input offset voltage. The reference voltage source comprises an input offset voltage elimination circuit, a band-gap reference source sub-circuit and a switch clock circuit, the input offset voltage elimination circuit is used for eliminating input offset voltage existing betweenthe non-inverting input end and the inverting input end of the operational amplifier and controlling the output end VBG voltage of the band-gap reference source sub-circuit; and the switch clock circuit is used for providing a clock signal for the input offset voltage elimination circuit, so that the input offset voltage elimination circuit alternately operates in a first working mode and a second working mode. Therefore, the input offset voltage elimination circuit eliminates the input offset voltage and keeps the output end VBG voltage of the band-gap reference source sub-circuit in a normal working state. And the precision of the output voltage of the voltage regulator is further improved.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to an improved voltage regulator. Background technique [0002] The reference voltage source is an important part of analog and mixed-signal integrated circuits, and it is widely used in the design of power management chips, voltage regulators and other circuits. The reference voltage source serves as a reference voltage or reference current for the entire circuit, and its performance directly affects the performance of the entire circuit. With the development of integrated circuits, the complexity of design has become higher and higher, and higher requirements have been put forward for the anti-interference ability of the reference voltage source. [0003] For example figure 1 A schematic circuit diagram of an existing complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, COMS) bandgap reference voltage source is shown. Such as figure 1 I...

AI Technical Summary

Problems solved by technology

[0005] Since V OS It has temperature characteristics, so the output offset voltage will not only have a greater impact on the output voltage of the CMOS bandgap reference voltage source circuit, but also have a greater impact on the temperature coefficient of the CMOS bandgap reference voltage source circuit

Therefore, due to the deviation of the generated bandgap reference voltage VGB, the final voltage value of the voltage regulator using such a bandgap reference voltage source is also inaccurate.

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