Magnetoresistive Current Sensor with Symmetric Conductive Structures
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Solution Overview
Problem
Conventional electric current sensors, such as Hall sensors, face issues with high temperature drift, low bandwidth, low accuracy, and a limited magnetic field range, as well as large bulk volume and high power consumption, making them inefficient for modern miniaturized electrical devices.
Innovation Solution
The development of an electric current sensor and sensing device utilizing a plurality of pairs of magnetic field sensors with symmetric conductive structures, including a horizontal magnetoresistive layer and conductive portions, integrated into a single chip, which can detect magnetic fields parallel and orthogonal to the substrate surface, and features a shield structure to eliminate external magnetic fields, enhancing sensitivity and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If Hall sensor is used for detecting electric current, then large magnetic field range can be achieved, but temperature drift increases, bandwidth decreases, and accuracy decreases
Solution Approach 1:
The sensor divides the detection function into multiple specialized magnetic field sensors (first sensor for Bx, second sensor for By, third sensor for Bz) arranged in specific orientations. Each sensor detects magnetic field components in specific directions, and their outputs are combined to achieve accurate current detection across a large magnetic field range while maintaining high accuracy through directional specialization.
Solution Approach 2:
Each magnetic field sensor is designed with specific local characteristics - different sensing directions and sensitivities. The first sensor detects Bx component, the second detects By component, and the third detects Bz component. This local quality differentiation allows the system to maintain high accuracy in each directional measurement while achieving comprehensive large-range detection capability.
2Measurement precision
If conventional MR sensor layout is used, then high accuracy can be achieved, but magnetic field range is limited and chip volume increases
Solution Approach 1:
The invention transitions from planar 2D sensor arrangement to 3D spatial configuration by utilizing magnetic field sensors oriented in different directions (x, y, z axes). This dimensional expansion allows the sensor to detect magnetic field vectors in three-dimensional space, significantly expanding the magnetic field range while maintaining compact chip footprint and high accuracy through vector synthesis.
3Reliability
If conventional sensor design is used, then detection function is provided, but volume and power consumption are high
Solution Approach 1:
The invention merges multiple detection functions into a single integrated sensor chip. Multiple magnetic field sensors with different orientations are combined on one chip, along with signal processing circuits that synthesize the outputs to detect current magnitude and direction. This integration achieves full 3D magnetic field detection capability in a compact volume, eliminating the need for separate sensors and reducing overall system size while maintaining reliable detection function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a high-accuracy, high-bandwidth, and low-temperature-drift magnetic field sensing capability with a large field range, while reducing the sensor's volume and power consumption, effectively addressing the limitations of conventional sensors.
Implementation Method 1
magentoresistance sensing measures such as anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), or tunnel magnetoresistance (TMR)
Implementation Method 2
detecting the electric current, and more particularly, to an electric current sensor and sensing device formed by magnetoresistance (MR) sensing elements
Data Source
AI summary
The present invention provides an electric current sensor comprising a substrate and MR sensing circuit. The substrate has a first surface along a first axis and a second axis. The MR sensing circuit is utilized to detect a magnetic filed about a third axis. The MR sensing circuit is formed onto the first surface and has a plurality of MR sensor pairs. Each MR sensor in each MR sensor pair has a plurality of conductive structures, wherein the conductive structures of one MR sensor are symmetrically arranged. Alternatively, the present invention provides an electric current sensing device using a pair of electric sensors symmetrically arranged at two lateral sides of a conductive wire having an electric current flowing therethrough for eliminating the magnetic field along Z axis generated by external environment.