Complementary metal oxide semiconductor (CMOS)-process-based Hall switch offset voltage elimination method and circuit

Abstract

The invention relates to a complementary metal oxide semiconductor (CMOS)-process-based Hall switch offset voltage elimination method and a CMOS-process-based Hall switch offset voltage elimination circuit. A first clock signal and a second clock signal which are not overlapped with each other are adopted based on a rotary current method, wherein the first clock signal controls the amplification and storage of Hall voltage when a Hall slice is in a 0-degree state, and divides the second clock signal into a third clock signal and a fourth clock signal; the third clock signal controls the amplification and storage of the Hall voltage in a 90-degree state; and the fourth clock signal controls operations and comparison between the Hall voltage and threshold voltage in the 0-degree state and the 90-degree state to eliminate the offset voltage of the Hall slice. Compared with the prior art, the invention can use relatively fewer components and parts based on a CMOS process, so that a Hall switch can be applied to the detection of weak magnetic fields under the requirements of miniaturization and low power consumption.

Description

technical field [0001] The invention relates to a Hall switch circuit, in particular to a method for eliminating the offset voltage of a Hall switch based on a CMOS process and a circuit thereof. Background technique [0002] Hall effect is a kind of magnetoelectric effect. This phenomenon was discovered by American physicist Hall (A.H.Hall, 1855-1938) in 1879 when he was studying the conductive mechanism of metals. When the current passes through the conductor perpendicular to the external magnetic field, a potential difference will appear between the two end faces of the conductor perpendicular to the magnetic field and the direction of the current. This phenomenon is the Hall effect, and this potential difference is also called the Hall voltage V H . [0003] The Hall sensor based on the Hall effect has developed into a diverse family of magnetic sensor products, which are more and more widely used in various fields of industrial control. The Hall switch is one of the a...

AI Technical Summary

Problems solved by technology

This method not only does not consider the offset voltage of the hysteresis comparator, but also cannot completely eliminate the influence of the offset voltage of the Hall sheet. As the Hall voltage further decreases, the influence of the offset voltage will gradually appear, and even affect the Hall switch. output state

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