Differential Hall Current Sensor Layout for Low-Noise Sensing
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Solution Overview
Problem
Conventional current sensors suffer from poor signal-to-noise ratios and high manufacturing costs, limiting their sensitivity and linearity.
Innovation Solution
A current sensor device utilizing a silicon substrate with two sensing areas, each containing magnetic sensing elements made of III-V semiconductor material, positioned near the edges of the substrate, and employing a processing circuit for signal compensation and offset reduction, eliminating the need for external shields or concentrators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Hall effect elements are fabricated on III-V semiconductor materials to increase sensitivity, then sensitivity and signal-to-noise ratio are improved, but manufacturing cost increases
Solution Approach 1:
The device is divided into two separate sensing areas (first and second sensing areas) on the silicon substrate, each with its own magnetic sensing element. This segmentation allows differential measurement that rejects common-mode noise while maintaining the benefits of III-V semiconductor sensing elements for high sensitivity
Solution Approach 2:
A processing circuit is introduced as an intermediary between the magnetic sensing elements and the output, which compensates for offset errors and processes signals from the two sensing areas. This intermediary circuit enables the system to achieve high measurement precision while working with the constraints of silicon substrate integration
2Ease of manufacture
If conventional current sensors are used, then manufacturing cost is kept low, but signal-to-noise ratio and sensitivity deteriorate
Solution Approach 1:
The invention uses a composite structure combining silicon substrate (for low-cost manufacturing and integration) with III-V semiconductor magnetic sensing elements (for high sensitivity). This composite approach allows the system to achieve high signal-to-noise ratio while maintaining compatibility with standard silicon fabrication processes and reasonable manufacturing costs
Solution Approach 2:
The patent merges the advantages of silicon substrate manufacturing (low cost, high integration) with the superior magnetic sensing properties of III-V semiconductor materials. By integrating both materials in a single device architecture with two sensing areas, the system achieves both cost-effectiveness and high performance
3Object-affected harmful factors
If magnetic sensing elements are positioned near edges of substrate, then sensitivity to external disturbances is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The two sensing areas are positioned asymmetrically near different edges of the substrate rather than symmetrically in the center. This asymmetric positioning near edges creates different sensitivity patterns to external disturbances, enabling the processing circuit to differentiate and reject common-mode noise while maintaining manufacturing feasibility
Solution Approach 2:
The processing circuit implements feedback mechanisms to compensate for positioning variations and offset errors. By continuously monitoring and adjusting for manufacturing tolerances in the positioning of sensing areas, the system achieves reduced sensitivity to external disturbances without requiring extremely tight manufacturing precision
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 device achieves improved sensitivity and signal-to-noise ratio while maintaining low manufacturing costs, with reduced sensitivity to external disturbances and enhanced linearity.
Implementation Method 1
The Hall effect is the production of a voltage difference (the Hall voltage) across an electrically conductive material (such as a wire), transverse to the electric current in the material and to an applied magnetic field perpendicular to the current.
Implementation Method 2
magnetoresistive materials whose electrical resistance changes in response to an external magnetic field
Data Source
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AI summary
The present invention relates to a current sensor device comprising : - a silicon substrate (2) having an active surface, - a first sensing area (10) disposed near a first edge of said active surface of said silicon substrate, said first sensing area comprising at least one first magnetic sensing element (12) made of a first compound semiconductor material and at least four contact pads (14), - a second sensing area (20) disposed near a second edge of said active surface of said silicon substrate, said second edge being substantially opposite to said first edge, said second sensing area comprising at least one second magnetic sensing element (22) made of a second compound semiconductor material and at least four contact pads (24), - a processing circuit (30) disposed in said silicon substrate and electrically connected via wire bonds and/or a redistribution layer with said contact pads of said first and of said second sensing area and arranged to derive a first signal (34) based on signals received from said at least one first magnetic sensing element of said first sensing area, to derive a second signal (36) based on signals received from said at least one second magnetic sensing elements of said second sensing area and to compute a difference (38) between said first and said second signal.