Semiconductor magnetic sensor

• US 20080150522A1
• Filed: 12/19/2007
• Published: 06/26/2008
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: Ablic Inc. (MinebeaMitsumi Inc.)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Hikichi, Tomoki
• Granted Patent: US 7,459,906 B2
• Time in Patent Office: Days
• US Class Current: 324/251
• CPC Class Codes: G01R 33/07 Hall effect devices

Abstract

To detect a magnetic flux density of a magnetic field applied from an outside, a semiconductor magnetic sensor of the present invention includes: a transistor (MP101) formed on a side of one, side of a hall element (100), for driving the hall element (100), the transistor (MP101) having a drain connected to a terminal (C101) formed on the one side; a transistor (MP102) formed on the side of the one side and having a drain connected to a terminal (C102) formed on the one side; a transistor (MN101) formed on a side of another side opposite to the one side and having a drain connected to a terminal (C103) formed on the another side; a transistor (MN102) formed on the side of the another side and having a drain connected to a terminal (C104) formed on the another side.

Claims

1. A semiconductor magnetic sensor for detecting a magnetic flux density of a magnetic field applied from an outside, comprising:

a hall element formed in one of a square shape and a rectangular shape, for performing magnetoelectric conversion;

a first transistor formed on a side of one side of the hall element, for driving the hall element, the first transistor having a drain connected to a first terminal formed on the one side of the hall element and having a source connected to a power supply terminal;

a second transistor formed on the side of the one side of the hall element, for driving the hall element, the second transistor having a drain connected to a second terminal formed on the one side of the hall element and having a source connected to the power supply terminal;

a third transistor formed on a side of another side opposite to the one side of the hall element, for driving the hall element, the third transistor having a drain connected to a third terminal formed on the another side of the hall element and having a source connected to a ground terminal; and

a fourth transistor formed on the side of the another side of the hall element, for driving the hall element, the fourth transistor having a drain connected to a fourth terminal formed on the another side of the hall element and having a source connected to the ground terminal.

2. A semiconductor magnetic sensor according to claim 1, wherein:

the drain of the third transistor is connected to the third terminal via a first wiring which has the same shape, in terms of mask layout, as that of a second wiring connecting the drain of the first transistor and the first terminal and rotated by 180 degrees; and

the drain of the fourth transistor is connected to the fourth terminal via a third wiring which has the same shape, in terms of mask layout, as that of a fourth wiring connecting the drain of the second transistor and the second terminal and rotated by 180 degrees.