CN102811044A

CN102811044A - Switch type hall sensor with temperature compensation and hysteresis comparator circuit

Info

Publication number: CN102811044A
Application number: CN 201110147811
Authority: CN
Inventors: 彭卓
Original assignee: SHANGHAI TENGYI SEMICONDUCTORS CO Ltd
Current assignee: SHANGHAI TENGYI SEMICONDUCTORS CO Ltd
Priority date: 2011-06-02
Filing date: 2011-06-02
Publication date: 2012-12-05

Abstract

The invention relates to a switch type hall sensor with the temperature compensation and a hysteresis comparator circuit. By adding a temperature compensating circuit in the hysteresis comparator circuit, the temperature drifting of the sensitivity of a hall piece is compensated, so that the hall sensor can still work regularly under a high-temperature environment. The temperature compensating circuit provided by the invention is composed of offset constant flow sources of a positive temperature coefficient and a negative temperature coefficient and formed by adopting a metal oxide semiconductor (MOS) transistor; and compared with the temperature compensating circuit consisting of a bipolar junction transistor (BJT) and a base resistance under the traditional bipolar technique, the temperature compensating circuit has smaller layout area and lower power consumption.

Description

The Hall switch sensor and the hysteresis comparator circuit of band temperature-compensating

Technical field

The present invention relates to a kind of Hall switch sensor circuit and hysteresis comparator circuit thereof with temperature-compensating.

Background technology

In the application of electric equipments such as motor, Hall switch sensor has progressively replaced traditional touch switch.Compare with traditional touch switch, the Hall switch integrated circuit has contactless, low-power consumption, long service life, operating frequency advantages of higher.It utilizes the Hall effect of semi-conducting material, detects the variation of external magnetic field, corresponding output high-low level.

The Hall effect of semi-conducting material is as shown in Figure 1, and the Hall plate of a rectangular shape is put into uniform magnetic field B, adds making alive at the Hall plate two ends, will produce Hall voltage V between the induction electrode of both sides _H

Hall voltage does

V _H＝wvB

In the following formula, w is the width of Hall plate, and v is a carrier mobility speed, and B is a magnetic field intensity.

Because when temperature raise, carrier mobility speed can descend, therefore under identical magnetic field intensity, the Hall voltage that Hall plate produces can reduce along with the rising of temperature.The Hall effect meeting temperature influence of this explanation semi-conducting material, its magnetic induction sensitivity raises along with temperature and reduces.

The applied environment range of temperature of Hall switch sensor is very wide, at high temperature, because the magnetic induction sensitivity of semi-conducting material descends, occurs detecting the situation of changes of magnetic field probably.Therefore, when utilizing the Hall effect manufacturing magnetic field sensor of semi-conducting material,, must the temperature drift of Hall plate sensitivity be compensated in order to guarantee the temperature performance of transducer.

Summary of the invention

Because the sensitivity of semiconductor Hall element increases with temperature and reduces, this characteristic influences the application of Hall element greatly, may cause the Hall element can't operate as normal under hot environment.The invention provides a kind of Hall circuit structure, the sluggish width of magnetic of the Hall element of switching mode is raise with temperature remain unchanged or slightly reduce, thereby guarantee the sensing switch performance with temperature-compensating.

The present invention is a Hall switch sensor, comprises pressurizer, Hall plate, and hysteresis comparator, output stage, wherein hysteresis comparator comprises transistor M1; Transistor M2, transistor M3, transistor M4, transistor M5, transistor M6, transistor M7; Transistor M8, transistor M9, transistor M10, transistor M11, transistor M12, transistor M13; Transistor M14, transistor M15, transistor M16, transistor M17, transistor M18; Biasing constant-current source Ib1, biasing constant-current source Ib2, phase inverter INV1, phase inverter INV2, phase inverter INV3.Wherein, transistor M1 and transistor M2 are as the input stage of comparator, and their source electrode links to each other, and connects the drain electrode of transistor M3, and their drain electrode connects the drain electrode of transistor M5 and transistor M6 respectively.Transistor M5 and transistor M7 connect into the CASCODE structure, and the grid of transistor M7 connects the drain electrode of grid and the M5 of transistor M10.Transistor M6 and transistor M8 constitute the CASCODE structure, and the grid of transistor M8 connects the drain electrode of grid and the M6 of transistor M9.Transistor M9 and transistor M11 connect into the CASCODE structure; The drain electrode of transistor M11 connects the drain electrode of transistor M13 and the drain electrode of transistor M17; The source electrode of transistor M17 meets biasing constant-current source Ib1; Transistor M13 and transistor M15 connect into the CASCODE structure, and transistor M15 source ground, transistor M15 grid connect transistor M13 drain electrode.Transistor M10 and transistor M12 connect into the CASCODE structure; The drain electrode of transistor M12 connects the drain electrode of transistor M18 and the drain electrode of transistor M14; The source electrode of transistor M18 meets biasing constant-current source Ib2; Transistor M14 and transistor M16 connect into the CASCODE structure, transistor M16 source ground, and transistor M14 drain electrode connects phase inverter INV1 input.The grid of phase inverter INV1 output termination phase inverter INV2 input and transistor M17, the grid of phase inverter INV2 output termination phase inverter INV3 input and transistor M18.

Wherein, the grid of transistor M1 and transistor M2 is as the input of comparator, and phase inverter INV3 is as the output of hysteresis comparator.Transistor M1, transistor M2, transistor M3, transistor M4, transistor M13, transistor M14, transistor M15, transistor M16 is a nmos pass transistor.Transistor M5, transistor M6, transistor M7, transistor M8, transistor M9, transistor M10, transistor M11, transistor M12, transistor M17, transistor M18 are the PMOS transistors.

The present invention makes Hall switch sensor can be operated under the higher ambient temperature through hysteresis comparator is increased temperature-compensating.When temperature raise, the electric sluggish width of hysteresis comparator can decrease, and can effectively remedy the problem that Hall plate sensitivity descends and brings.

The present invention is through increasing temperature-compensation circuit, and the temperature drift of the magnetic induction sensitivity of Hall plate is compensated, and makes the retarding window width of comparator when temperature raises, reduce, thereby guarantees the operate as normal of Hall switch sensor under hot environment.Hysteresis comparator and temperature-compensation circuit adopt MOS transistor to constitute; The temperature-compensation circuit that constitutes by BJT transistor AND gate base resistance under traditional bipolar technology; Shared chip area is littler, and power consumption is lower, and can more effective adjusting temperature-compensating degree.

Description of drawings

Fig. 1 is the Hall plate sketch map;

Fig. 2 is conventional Hall switch sensor integrated circuit sketch map;

Fig. 3 is the hysteresis comparator circuit structural representation of Hall element of the present invention;

Fig. 4 is a Hall element negative temperature coefficient constant current source generating circuit of the present invention.

Embodiment

Because the magnetic induction sensitivity of Hall plate reduces with the rising of temperature, this will cause the magnetic retarding window width of Hall switch sensor under the high-temperature work environment to become big, thereby can influence its operate as normal.In order to ensure the operate as normal of Hall switch sensor under high-temperature work environment, need float the temperature of Hall plate sensitivity and compensate, make the sluggish width of magnetic of Hall element when temperature raises, remain unchanged.

The present invention discloses a kind of hysteresis comparator circuit with temperature compensation function, and the hysteresis comparator circuit structure is as shown in Figure 3.

This hysteresis comparator one total two-stage, the first order realizes the difference amplification, by transistor M1, transistor M2, transistor M3, transistor M5, transistor M6, transistor M7, transistor M8 constitutes.Sluggish output is realized in the second level, by transistor M9, and transistor M10, transistor M11; Transistor M12, transistor M13, transistor M14, transistor M15; Transistor M16, transistor M17, the transistor M18 and the constant current Ib1 in a steady stream that setovers; The biasing constant current is Ib2 and phase inverter INV1 in a steady stream, phase inverter INV2, and phase inverter INV3 constitutes.Biasing constant-current source Ia is a positive temperature coefficient, and when promptly temperature raise, current value increased.Biasing constant-current source Ib1 and biasing constant-current source Ib2 equal and opposite in direction, temperature coefficient is identical and be negative, and when promptly temperature raise, biasing constant-current source Ib1 reduced with biasing constant-current source Ib2 current value.

It is as shown in Figure 4 with the circuit of biasing constant-current source Ib2 to produce biasing constant-current source Ib1, and it comprises transistor M19, transistor M20, transistor M21, transistor M22, transistor Q1, resistance R 1.Wherein, transistor M19 and transistor M20 connect into current-mirror structure, and transistor M20 grid connects its drain electrode, and transistor M21 and transistor M22 connect into current-mirror structure, and transistor M21 grid connects its drain electrode.The drain electrode of transistor M21 connects the drain electrode of transistor M19, and the source electrode of transistor M21 connects collector electrode and the base stage of transistor Q1, transistor Q1 grounded emitter.The drain electrode of transistor M22 connects the drain electrode of transistor M20, the source electrode connecting resistance R1 of transistor M22, resistance R 1 other end ground connection.

Biasing constant-current source Ib1 and biasing constant-current source Ib2 adopt suitable size and negative temperature coefficient can obtain required effect temperature compensation.

Claims

1. the present invention is a kind of Hall switch sensor, comprises pressurizer, biasing constant current source generating circuit, Hall plate, hysteresis comparator, output stage.Wherein hysteresis comparator circuit comprises transistor M1, transistor M2, transistor M3, transistor M4, transistor M5, transistor M6; Transistor M7, transistor M8, transistor M9, transistor M10, transistor M11, transistor M12; Transistor M13, transistor M14, transistor M15, transistor M16, transistor M17, transistor M18; Biasing constant-current source Ib1, biasing constant-current source Ib2, phase inverter INV1, phase inverter INV2, phase inverter INV3.Wherein, transistor M1 and transistor M2 are as the input stage of comparator, and their source electrode links to each other, and connects the drain electrode of transistor M3, and their drain electrode connects the drain electrode of transistor M5 and transistor M6 respectively.Transistor M5 and transistor M7 connect into the CASCODE structure, and the grid of transistor M7 connects the drain electrode of grid and the M5 of transistor M10.Transistor M6 and transistor M8 constitute the CASCODE structure, and the grid of transistor M8 connects the drain electrode of grid and the M6 of transistor M9.Transistor M9 and transistor M11 connect into the CASCODE structure; The drain electrode of transistor M11 connects the drain electrode of transistor M13 and the drain electrode of transistor M17; The source electrode of transistor M17 meets biasing constant-current source Ib1; Transistor M13 and transistor M15 connect into the CASCODE structure, and transistor M15 source ground, transistor M15 grid connect transistor M13 drain electrode.Transistor M10 and transistor M12 connect into the CASCODE structure; The drain electrode of transistor M12 connects the drain electrode of transistor M18 and the drain electrode of transistor M14; The source electrode of transistor M18 meets biasing constant-current source Ib2; Transistor M14 and transistor M16 connect into the CASCODE structure, transistor M16 source ground, and transistor M14 drain electrode connects phase inverter INV1 input.The grid of phase inverter INV1 output termination phase inverter INV2 input and transistor M17, the grid of phase inverter INV2 output termination phase inverter INV3 input and transistor M18.

2. require the hysteresis comparator circuit of 1 described Hall switch sensor circuit like patent; Wherein, The grid of transistor M1 and transistor M2 is connected two induction electrodes of Hall plate respectively as the input of comparator, and phase inverter INV3 is as the output of hysteresis comparator.Transistor M1, transistor M2, transistor M3, transistor M4, transistor M13, transistor M14, transistor M15, transistor M16 is a nmos pass transistor.Transistor M5, transistor M6, transistor M7, transistor M8, transistor M9, transistor M10, transistor M11, transistor M12, transistor M17, transistor M18 are the PMOS transistors.

3. require 1 described hysteresis comparator circuit like patent, the constant-current source Ia that it is characterized in that setovering is a positive temperature coefficient, and biasing constant-current source Ib1 and biasing constant-current source Ib2 are negative temperature coefficient.