Rail-to-rail output linear Hall sensor circuit with adjustable sensitivity

Abstract

A rail-to-rail output linear Hall sensor circuit with adjustable sensitivity includes a Hall element, a sampling and holding circuit, a chopper amplifier circuit, a dynamic offset elimination circuit,a low-pass filter circuit, a sensitivity control circuit and a proportional rail-to-rail output circuit. The linear Hall sensor circuit of the invention is compatible with a CMOS process, the Hall element is realized by the N-well in the CMOS process, and the advantages of high sensitivity and good consistency of sensors can be realized. The circuit adopts voltage-type MOS devices, and has low power consumption. By adopting a rail-to-rail output structure, the output linearity can be 0.1V greater than the ground voltage and 0.1V less than the supply voltage. Moreover, the sensitivity of the circuit can be adjusted by the external feedback resistance of a rail-to-rail output amplifier structure, and the advantage of adjustable sensitivity is realized.

Description

technical field [0001] The invention relates to a linear Hall sensor circuit, in particular to a rail-to-rail output linear Hall sensor circuit with adjustable sensitivity. Background technique [0002] The Hall sensor chip is a monolithic circuit that integrates Hall elements and signal processing circuits on the same chip using microelectronics technology. It is a widely used magnetic field sensor at present. It can be used not only for magnetic field measurement, but also for current, speed The measurement of physical quantities such as , position, and angle has been widely used in automotive electronics, smart grid, precision measurement, industrial automation, household appliances, and emerging consumer electronics. [0003] In the linear Hall sensor of the traditional bipolar process, the Hall element is realized by the epitaxial layer. The sensitivity of the product is due to the large thickness and unevenness of the epitaxial layer. At the same time, due to the influ...

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Problems solved by technology

[0003] In the linear Hall sensor of the traditional bipolar process, the Hall element is realized by the epitaxial layer. The sensitivity of the product is due to the large thickness and unevenness of the epitaxial layer. At the same time, due to the influence of manufacturing process drift, packaging stress and other factors, the magnetic field sensitivity is low and the fluctuation is large. large, poor consistency, and low yield; the linear Hall sensor of the traditional bipolar process uses a current-mode triode device in the circuit implementation, which consumes a large amount of power and is not suitable for low-power applications. In addition, its linear output The range is narrow, generally greater than the ground voltage of 0.7V and less than the range of the power supply voltage of 0.7V, which is limited in application

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