Magnetic sensor device

Patent metadata

Field	Value
Publication number	US-9267818-B2
Application number	US-201414184219-A
Country	US
Kind code	B2
Filing date	Feb 19, 2014
Priority date	Feb 21, 2013
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

Provided is a magnetic sensor device capable of performing signal processing at high speed with high accuracy. The magnetic sensor device includes: a plurality of Hall elements; a plurality of differential amplifiers to which the plurality of Hall elements are connected, respectively; a detection voltage setting circuit for outputting a reference voltage; and a comparator including: a plurality of differential input pairs connected to the plurality of differential amplifiers, respectively; and a differential input pair connected to the detection voltage setting circuit.

First claim

What is claimed is:

1. A magnetic sensor device for outputting a signal in accordance with an intensity of a magnetic field applied to a Hall element, the magnetic sensor device comprising:
a plurality of Hall elements;
a plurality of differential amplifiers to which the plurality of Hall elements are connected, respectively;
a reference voltage generation circuit configured to output at least one reference voltage; and
a comparator comprising:
a plurality of differential input pairs connected to the plurality of differential amplifiers for outputting amplified signal voltages, respectively; and
a differential input pair connected to the reference voltage generation circuit configured to output a second reference voltage, and wherein the comparator is configured to output a result of comparison of the amplified voltages.

2. A magnetic sensor device according to claim 1 ,
wherein the plurality of differential amplifiers comprise:
a first differential amplifier comprising:
a first input terminal and a second input terminal respectively connected to an output terminal pair of a first Hall element; and
a first output terminal and a second output terminal for outputting amplified signal voltages; and

a second differential amplifier comprising:
a first input terminal and a second input terminal respectively connected to an output terminal pair of a second Hall element; and
a first output terminal and a second output terminal for outputting amplified signal voltages,

wherein the reference voltage generation circuit is configured to output a second reference voltage,
wherein the comparator comprises:
a first differential input pair including a first input terminal and a second input terminal respectively connected to the first output terminal and the second output terminal of the first differential amplifier;
a second differential input pair including a first input terminal and a second input terminal respectively connected to the first output terminal and the second output terminal of the second differential amplifier; and
a third differential input pair including a first input terminal and a second input terminal respectively connected to the first reference voltage and the second reference voltage.

3. A magnetic sensor device according to claim 1 , further comprising a differential amplifier provided between the reference voltage generation circuit and the differential input pair of the comparator.

Assignees

• Seiko Instr Inc

Inventors

• Muraoka Daisuke
• Ariyama Minoru
• Hikichi Tomoki
• Fukai Kentaro

Classifications

• H03K17/9517

  using galvanomagnetic devices · CPC title

• G01D5/145 Primary

  influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06) · CPC title

• G01R33/07

  Hall effect devices · CPC title