a voltage regulator

Abstract

The invention provides a voltage regulator, which adopts a reference voltage source that automatically eliminates input offset voltage. The reference voltage source includes: an input offset voltage elimination circuit, a bandgap reference source sub-circuit and a switch clock circuit; the input offset voltage elimination circuit is used to eliminate the input offset voltage existing between the same input terminal and the reverse input terminal of the operational amplifier , and control the output terminal VBG voltage of the bandgap reference source subcircuit; the switching clock circuit is used to provide a clock signal for the input offset voltage elimination circuit, so that the input offset voltage elimination circuit operates alternately in the first working mode and the second working mode. In order to eliminate the input offset voltage by the input offset voltage elimination circuit, and maintain the voltage at the output terminal VBG of the bandgap reference source subcircuit in a normal working state. Furthermore, the precision of the output voltage of the voltage regulator is 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] E.g figure 1 A schematic circuit diagram of an existing complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, COMS) bandgap reference voltage source is shown. like figure 1 It can be se...

AI Technical Summary

Problems solved by technology

[0007] 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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