MAGNETIC SENSOR INTEGRATED CIRCUIT, MOTOR ASSEMBLY AND APPLICATION DEVICE

• US 20170310253A1
• Filed: 04/19/2017
• Published: 10/26/2017
• Est. Priority Date: 04/20/2016
• Status: Active Grant

• Current Assignee: Johnson Electric International AG (Johnson Electric Holdings Limited)
• Original Assignee: Johnson Electric SA 125 Rue de Progres La Chaux de Fonds Switzerland (Johnson Electric Holdings Limited)
• Inventors: CAI, Guang Jie, WONG, Chun Fai
• Granted Patent: US 10,305,400 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 33/0082 Compensation, e.g. compensating for temperature changes
• CPC Class Codes: G01R 33/07 Hall effect devices
• CPC Class Codes: H02K 11/215 Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements

Abstract

A magnetic sensor integrated circuit is provided, which includes: a magnetic sensing element to detect change in an external magnetic field to output a magnetic field sensing signal; a signal processor to process the magnetic field sensing signal and output a magnetic field detection signal; and a current source generator to output a constant current to the magnetic sensing element. The constant current is not influenced by a temperature.

Claims

1. A magnetic sensor integrated circuit, comprising:

a magnetic sensing element detecting a polarity of an external magnetic field and outputting a magnetic field sensing signal;

a signal processor processing the magnetic field sensing signal and outputting a magnetic field detection signal; and

a current source generator outputting a constant current, which is not influenced by a temperature, to the magnetic sensing element.

2. The magnetic sensor integrated circuit according to claim 1, wherein the current source generator comprises:

a voltage source outputting a reference voltage; and

a temperature compensating resistor connected to the voltage source, wherein the voltage source outputs the constant current to the magnetic sensing element via the temperature compensating resistor.

3. The magnetic sensor integrated circuit according to claim 2, wherein the voltage source is a bandgap reference voltage source which converts a direct current voltage and output the reference voltage.

4. The magnetic sensor integrated circuit according to claim 2, wherein the current source generator further comprises at least one ordinary resistor, and the voltage source outputs at least one current via the at least one ordinary resistor.

5. The magnetic sensor integrated circuit according to claim 2, wherein the temperature compensating resistor comprises a positive temperature coefficient compensating resistor and a negative temperature coefficient compensating resistor connected in series.

6. The magnetic sensor integrated circuit according to claim 5, wherein the positive temperature coefficient compensating resistor is a first doping type of polysilicon resistor, and the negative temperature coefficient compensating resistor is a second doping type of polysilicon resistor.

7. The magnetic sensor integrated circuit according to claim 3, wherein the bandgap reference voltage source is a bipolar junction transistor core circuit.

8. The magnetic sensor integrated circuit according to claim 7, wherein the bipolar junction transistor core circuit comprises at least two triodes.

9. The magnetic sensor integrated circuit according to claim 1, wherein the signal processor comprises:

an amplifier amplifying the magnetic field sensing signal;

a switched capacitor filter sampling and filtering the magnetic sensing signal to eliminate a deviation signal; and

an analog-to-digital converter converting a filtered signal processed by the switched capacitor filter into a switch-type detection signal.

10. The magnetic sensor integrated circuit according to claim 9, wherein the amplifier is a chopper amplifier.

11. The magnetic sensor integrated circuit according to claim 1, wherein the magnetic sensing element is a Hall element.

12. The magnetic sensor integrated circuit according to claim 1, further comprising:

an AC-DC converter converting an alternating current voltage into a direct current voltage and providing the direct current voltage for the current source generator.

13. A motor assembly, comprising the magnetic sensor integrated circuit according to claim 1.

14. An application device, comprising the motor assembly according to claim 13.

15. The application device according to claim 14, wherein the application device is a pump, a fan, a household appliance or a vehicle.