Hall Sensor Circuit Spinning Current Spike Suppression
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Solution Overview
Problem
The existing continuous-time Hall electromotive force signal detection circuit using silicon Hall elements and spinning current techniques suffers from spike-like error signals that hinder high-precision current sensing, as the technique described in PTL 1 is unsatisfactory in suppressing these variations.
Innovation Solution
A Hall electromotive force signal detection circuit is designed with multiple Hall elements driven by spinning current techniques and transconductance amplifiers, incorporating a feedback network controller and Hall signal feedback network to stabilize the gm values of the amplifiers, ensuring equal operating points and canceling out spike signals by arithmetic averaging of Hall common voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spinning current technique is used to cancel offset voltage in Hall elements, then offset cancellation is achieved, but spike-like error signals are generated that hinder high-precision detection
Solution Approach 1:
The patent implements feedback control by detecting the Hall common voltage and comparing it with a reference voltage, then adjusting the drive current through a feedback amplifier to minimize the difference. This feedback mechanism suppresses spike-like error signals by continuously correcting deviations from the desired operating point, thereby maintaining measurement precision while eliminating harmful artifacts generated by the spinning current technique.
Solution Approach 2:
The patent dynamically adjusts the drive current parameter based on the detected Hall common voltage to optimize performance. By changing the drive current in response to detected voltage variations, the system suppresses spike-like errors while maintaining effective offset cancellation, resolving the contradiction between precision and harmful signal generation.
2Object-affected harmful factors
If continuous-time signal processing circuit is used, then noise-folding phenomenon is avoided and high-frequency noise resistance is improved, but circuit complexity increases
Solution Approach 1:
The patent divides the continuous-time signal processing into functional segments: Hall element array, spinning current switching circuit, transconductance amplification stage, feedback detection circuit, and output stage. This segmentation allows continuous-time processing to be implemented without requiring a completely complex monolithic structure, as each segment performs a specific function that contributes to noise rejection while maintaining manageable circuit complexity.
Solution Approach 2:
The patent designs the circuit components to serve multiple functions. For example, the transconductance amplifiers not only amplify the Hall signal but also provide impedance matching and contribute to noise filtering. The feedback circuit simultaneously detects Hall common voltage and generates correction signals. This multi-functionality reduces overall circuit complexity while maintaining continuous-time processing advantages.
3Measurement precision
If multiple Hall elements are used with spinning current techniques, then offset cancellation performance is improved, but variations in spike-like error signals increase
Solution Approach 1:
The patent connects multiple Hall elements in parallel with identical configurations and applies the same spinning current technique to all elements. This homogeneous arrangement ensures that spike-like error signals generated by each element have the same characteristics and phase relationships, allowing them to cancel each other out through coherent addition rather than creating unpredictable variations. The feedback circuit further enforces homogeneity by applying uniform correction signals to all elements.
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 effectively suppresses variations in spike-like error signals, enabling higher-precision detection of Hall electromotive force signals and improving the accuracy of current sensors by stabilizing the gain and reducing gain errors.
Implementation Method 1
A magnetic sensor using Hall elements is not only used as a sensor for detecting positional information of a magnet... but also widely used in applications for a current sensor for contactlessly measuring the amount of current flowing through a current conductor by detecting a magnetic field induced by the current flowing therethrough
Data Source
Figure 1
Figure 2A~2D
Figure 3A~3D
AI summary
A Hall electromotive force signal detection circuit suppresses variations of spike-like error signals that become obstacles to high-precision detection of Hall electromotive force signals. To this end, in the Hall electromotive force signal detection circuit driving plural Hall elements by spinning current techniques and using plural transconductance amplifiers, a reference signal Vcom is supplied from a feedback network controller (32) to a Hall signal feedback network (31) that performs a feedback control so that common voltages of Hall electromotive force signals from the plural Hall elements match with the reference signal Vcom and to an output signal feedback network (20) that feeds back a voltage obtained by dividing a difference between an output voltage and the reference signal Vcom. In this manner, the variations of spike signals are suppressed.