Hall switch circuit with temperature compensation

Abstract

The invention relates to a Hall switch circuit with temperature compensation, comprising a voltage stabilizer, a Hall induction sheet, a Hall voltage difference amplifier, a hysteresis comparator and an output unit, wherein the Hall induction sheet is connected between the output and an earth wire of the voltage stabilizer; two input ends of the Hall voltage difference amplifier are respectively connected with the Hall induction sheet; the hysteresis comparator is connected with the output end of the Hall voltage difference amplifier; and the output unit is connected with the input end of the hysteresis comparator. The Hall switch circuit is characterized in that the Hall voltage difference amplifier comprises a difference input pair, a current source and a load resistor, wherein the difference input pair consists of two transistors; the current source offsets the difference input pair and is directly proportional to absolute temperature; and the load resistor is respectively in series connected with the transistors of the difference input pair and is made from materials the same as that of the Hall induction sheet. The Hall switch circuit can eliminate the influence of microhenry temperature coefficient without special requirement for a process and is well controlled.

Description

technical field [0001] The invention relates to a Hall switch circuit, in particular to a Hall switch circuit with temperature compensation. Background technique [0002] The principle of the Hall effect is: for a suitable Hall material, if V is energized along its X direction R , if a magnetic field B is applied in the Y direction, a voltage V will appear in the Z direction H , V H Called the Hall voltage, it is related to the magnetic field B, the voltage V R The relationship with the material itself is [0003] V H = μ H BV R W L σ ( L W ) - - - ( 1 ) [0004] Where L, W are the length and width of the Hall material, is the geometry correction factor, μ H is the Hall mobility. [0005]...

AI Technical Summary

Problems solved by technology

This method makes the second-order characteristics more difficult to control; considering the drift of material characteristics, the consistency after mass production is also difficult to guarantee

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