SINGLE CHIP REFERENCED BRIDGE MAGNETIC SENSOR FOR HIGH-INTENSITY MAGNETIC FIELD

摘要

A single chip referenced bridge type magnetic field sensor for high-intensity magnetic field, the sensor comprises a substrate, a reference arm, a sense arm, shielding structures and attenuators. Wherein the reference arms and the sense arms comprise at least two rows/columns of reference element strings and sense element strings which comprise one or more identical electrically interconnected magnetoresistive sense elements; the reference element strings and the sense element strings are mutually interleaved, each reference element string is designed with a shielding structure on top of it, and each sense element string is designed with an attenuator on top of it. The magnetoresistive sensor elements can be AMR, GMR or TMR sensor elements. The shielding structures and attenuators are arrays of long rectangular bars composed of a soft ferromagnetic material, such as permalloy. The sensor may be implemented in three different bridge structures, a quasi-bridge, a referenced half-bridge, and a referenced full-bridge. This sensor has several advantages including low power consumption, excellent linearity, and wide working range making it able to operate in high-intensity magnetic fields.

主权项

1. A single chip referenced bridge type magnetic field sensor for a high-intensity magnetic field the sensor comprising:
a substrate; at least one reference arm deposited on the substrate, the reference arm comprising at least one row/column of reference element strings which comprise one or at least two identical electrically interconnected magnetoresistive sense elements; at least one sense arm deposited on the substrate, the sense arm comprising at least one row/column of sense element strings which comprise one or at least two identical electrically interconnected magnetoresistive sense elements; and at least one attenuator and at least two shielding structures, the attenuator and the shielding structures being mutually interleaved in a spaced manner, shapes of the attenuator and the shielding structures being the same, and width and area of the shielding structures being respectively greater than width and area of the attenuator; wherein the reference arm and the sense arm are connected to form a bridge; wherein each reference element string is designed with a shielding structure on top of it, each sense element string is designed with an attenuator on top of it, the reference element strings are located below or above the shielding structures and the sense element strings are located below or above the attenuators; wherein the reference element strings and the sense element strings are the same in number of rows/columns and are mutually interleaved in a spaced manner along a longitudinal or transverse direction; and wherein a gain coefficient of a magnetic field at the position of the sense element strings is greater than a gain coefficient of a magnetic field at the position of the reference element strings.