Dual-Sensitivity Current Sensing With Dynamic Offset Correction
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Solution Overview
Problem
Conventional sensors require zero-input offset calibration and quiescent voltage trimming due to inaccuracies caused by offsets in sensing signals, which can introduce measurement errors.
Innovation Solution
A sensor system that measures electrical current using two sensitivities or internal amplifier gains to dynamically correct zero-current offset by simultaneously measuring current through different sensitivities, eliminating the need for zero-input offset calibration and quiescent voltage trimming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors use single sensitivity measurement, then device complexity is reduced, but measurement precision deteriorates due to offset errors
Solution Approach 1:
The measurement process is segmented into multiple sensitivity levels. The sensor divides the measurement task by taking measurements at different gain levels (first gain and second gain), allowing offset errors to be identified and corrected through the differential analysis of these segmented measurements.
Solution Approach 2:
The patent adds a dimensional aspect to measurement by introducing multiple gain levels. Instead of single-point measurement, the system measures at different sensitivity dimensions (gains), creating a multi-dimensional measurement space where offset errors can be mathematically eliminated.
2Measurement precision
If zero-input offset calibration is performed, then measurement precision is improved, but productivity decreases due to additional calibration steps
Solution Approach 1:
The sensor performs self-calibration by using its own multiple sensitivity measurements to identify and correct offset errors. The system serves its own calibration needs through the dynamic offset correction mechanism, eliminating the requirement for external zero-input calibration procedures.
Solution Approach 2:
The offset correction is performed preliminarily within the normal measurement process. By continuously calculating and applying offset corrections based on multi-gain measurements, the system prepares and maintains accurate measurements without requiring separate pre-calibration actions.
3Measurement precision
If high gain amplification is used, then measurement precision for small signals is improved, but reliability deteriorates due to saturation at higher signal levels
Solution Approach 1:
The system dynamically switches between different gain levels based on signal conditions. By adaptively selecting between first gain and second gain modes, the sensor maintains optimal precision across varying signal amplitudes while avoiding saturation, thus dynamically adjusting to maintain reliability.
Solution Approach 2:
The patent changes the amplification parameter (gain) based on measurement requirements. By varying the gain parameter between two distinct levels, the system optimizes the balance between precision for small signals and reliability for larger signals, preventing amplifier saturation.
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 measurement inaccuracies by dynamically correcting offsets, enhancing sensor precision without the need for additional calibration steps.
Implementation Method 1
Some sensors include one or more electromagnetic flux sensing elements, such as a Hall effect element, a magnetoresistive element, or a receiving coil to sense an electromagnetic flux associated with proximity or motion of a target object
Data Source
AI summary
A method is provided for use in a sensor, comprising: generating a sensing signal by using one or more sensing elements; amplifying the sensing signal by using a first gain to produce, at least in part, a first amplified signal, the first amplified signal having a first offset; amplifying the sensing signal by using a second gain to produce, at least in part, a second amplified signal, the second amplified signal having a second offset; generating an adjusted signal based on the first amplified signal, the second amplified signal, the first gain, and the second gain, the adjusted signal approximating a difference between the second amplified signal and an offset of the second amplified signal; and using the adjusted signal to generate an output of the sensor.