Time-Multiplexed Biasing Circuit for AMR Sensor Energy Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic-field sensors, particularly anisotropic magnetoresistive (AMR) sensors, face high energy consumption due to the continuous supply of biasing voltage to multiple detection structures, which is problematic in battery-supplied portable applications where energy usage is a critical design constraint.
Innovation Solution
A biasing circuit that supplies detection structures in non-overlapping, distinct time intervals, coupled with a single reading circuit that operates during these intervals, significantly reducing overall energy consumption by minimizing simultaneous energy usage across all detection structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous biasing voltage is supplied to multiple detection structures, then reliable magnetic field detection is maintained, but energy consumption increases significantly
Solution Approach 1:
The patent implements periodic sampling of detection structures by activating biasing voltage for each detection structure in sequential time intervals rather than continuously. The biasing circuit activates the first detection structure during a first time interval, then the second detection structure during a second time interval, creating a periodic measurement cycle that reduces average power consumption while maintaining detection reliability through time-multiplexed readings
Solution Approach 2:
The patent introduces dynamic control of the biasing circuit to switch between different detection structures based on timing signals. The biasing circuit's activation state changes dynamically between time intervals, enabling the system to adapt power distribution to measurement requirements rather than maintaining static continuous power supply to all structures simultaneously
2Adaptability or versatility
If multiple detection structures are supplied simultaneously, then comprehensive magnetic field component detection is achieved, but area occupation increases
Solution Approach 1:
The patent merges the reading operations for multiple detection structures into a single reading circuit that serves all structures sequentially. The reading circuit is shared across detection structures and activated during respective time intervals, consolidating what would otherwise require separate dedicated reading circuits for each detection structure, thereby reducing the overall area occupied by reading circuitry in the integrated implementation
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
This approach reduces energy consumption by up to one-third compared to continuous supply methods, while also optimizing area occupation in integrated implementations, particularly beneficial for triaxial sensors.
Implementation Method 1
the phenomenon of anisotropic magnetoresistivity occurs within particular ferrous materials, which, when subjected to an external magnetic field, undergo a variation of resistivity as a function of the characteristics of the external magnetic field
Implementation Method 2
coils or straps, which are integrated in the same AMR sensors, and are designed to generate, when traversed by current, a magnetic field with pre-defined direction and sense
Data Source
AI summary
Described herein is a biasing circuit for a magnetic-field sensor; the magnetic-field sensor is provided with a first detection structure, which generates a first electrical detection quantity as a function of a first component of an external magnetic field, and a second detection structure, which generates a second electrical detection quantity as a function of a second component of an external magnetic field. The biasing circuit electrically supplies the first detection structure and the second detection structure in respective biasing time intervals, at least partially distinct from one another, which preferably do not temporally overlap one other.