Dual-Gain Sensor Offset Correction for High Dynamic Range
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Solution Overview
Problem
Conventional sensors require zero-input offset calibration and quiescent voltage trimming, which can be cumbersome and inefficient.
Innovation Solution
A method and system for dynamically correcting zero-current offset voltage by simultaneously measuring current through two distinct sensitivities using different amplifier gains, eliminating the need for zero-input offset calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors use zero-input offset calibration and quiescent voltage trimming, then measurement accuracy can be improved, but the device complexity and calibration time increase
Solution Approach 1:
The sensor performs self-calibration by automatically calculating and applying offset corrections using its own amplified signals at different gains, eliminating the need for external calibration equipment and manual trimming procedures. The system uses its inherent dual-gain architecture to generate calibration data and compute corrections autonomously.
Solution Approach 2:
The sensor performs offset calibration dynamically during operation rather than requiring separate pre-calibration steps. The calibration process is integrated into the normal measurement workflow, allowing the system to prepare and apply corrections in advance of actual measurements without disrupting the measurement process.
2Measurement precision
If conventional sensors perform offset calibration, then offset voltage inaccuracies are reduced, but the calibration time and productivity are decreased
Solution Approach 1:
The sensor performs offset calibration periodically or dynamically during normal operation rather than requiring a separate calibration phase. The system can quickly switch between measurement and calibration modes, performing brief calibration cycles that minimize disruption to productivity while maintaining accurate offset correction.
Solution Approach 2:
The sensor performs offset calibration dynamically during operation rather than requiring separate pre-calibration steps. The calibration process is integrated into the normal measurement workflow, allowing the system to prepare and apply corrections in advance of actual measurements without disrupting the measurement process.
3Device complexity
If the sensor uses a single gain amplifier, then the device complexity is reduced, but the dynamic range and measurement precision are limited
Solution Approach 1:
The sensor dynamically switches between different amplifier gains based on the input signal level. The system automatically selects appropriate gain settings to optimize measurement precision across the full dynamic range, using higher gains for small signals and lower gains for large signals without requiring multiple fixed-gain amplifier stages.
Solution Approach 2:
The sensor changes the amplifier gain parameter dynamically based on signal conditions. By adjusting the gain setting according to the input signal amplitude, the system extends its effective dynamic range and maintains measurement precision across varying signal levels using a single reconfigurable amplifier.
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 enhances measurement accuracy by eliminating the need for calibration and trimming, thereby improving sensor performance and reducing inaccuracies due to offset voltages.
Implementation Method 1
Some sensors include one or more electromagnetic flux sensing elements, such as a Hall effect element
Implementation Method 2
Some sensors include one or more electromagnetic flux sensing elements, such as a Hall effect element, a magnetoresistive element
Implementation Method 3
Some sensors include one or more electromagnetic flux sensing elements, such as a receiving coil to sense an electromagnetic flux
Data Source
Figure 1A
Figure 1B
Figure 1C
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.