Current Sensor Fault Detection Shared Signal Path
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Solution Overview
Problem
Conventional current sensors require additional analog circuitry for out-of-range detection, which increases power consumption and circuit area, and lack efficient fault detection mechanisms for overcurrent conditions.
Innovation Solution
A current sensor design incorporating a shared signal path with magnetic field sensing elements, chopping modules, amplifiers, and an analog-to-digital converter, along with separate fault detection and main signal paths that share components to reduce power and size requirements, enabling simultaneous fault detection and signal processing with different processing speeds for accurate and fast overcurrent detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional analog circuitry is used for out-of-range detection, then fault detection capability is improved, but power consumption and circuit area increase
Solution Approach 1:
The patent combines the fault detection function with the existing digital signal processing path by using the ADC and digital filters to process both normal current signals and fault detection signals. The digital overcurrent detection circuit shares resources with the main signal processing path, eliminating the need for separate analog fault detection circuitry and reducing overall power consumption and circuit area.
Solution Approach 2:
The patent replaces traditional analog fault detection circuitry with a digital implementation. By using the ADC to convert signals to digital domain and then using digital filters and comparators for overcurrent detection, the system eliminates power-hungry analog comparison circuits while maintaining fault detection capability.
2Reliability
If additional analog circuitry is used for out-of-range detection, then fault detection capability is improved, but circuit area increases
Solution Approach 1:
The patent merges the fault detection functionality into the existing digital signal processing infrastructure. The ADC, digital filters, and comparators are shared between normal current measurement and fault detection functions, significantly reducing the additional circuit area that would be required for separate analog fault detection circuitry.
Solution Approach 2:
The digital signal processing components (ADC, filters, comparators) are designed to serve multiple functions: normal current measurement and fault detection. This multi-functionality allows the system to achieve fault detection capability without adding dedicated circuit area for separate fault detection hardware.
3Speed
If fault detection signal path has faster processing rate, then fault detection speed is improved, but processing accuracy may be reduced
Solution Approach 1:
The patent segments the signal processing into two distinct paths with different processing rates: a fast fault detection path using oversampling and a slower main signal path with higher filtering. The fast path uses a higher sampling rate to quickly detect overcurrent conditions, while the main path uses lower sampling rate with more aggressive filtering for accurate current measurement, allowing each path to be optimized for its specific purpose.
Solution Approach 2:
The system dynamically adjusts processing rates for different signal paths based on the detection needs. The fault detection path operates at a higher processing rate to quickly identify unsafe conditions, while the main signal path operates at a lower rate for accurate current measurement. This dynamic processing rate adjustment allows the system to maintain both speed and accuracy where needed.
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 solution achieves low latency fault detection with reduced kick-back noise and power consumption, allowing for efficient detection of overcurrent conditions while maintaining high-resolution output signals, thus addressing the limitations of conventional sensors.
Implementation Method 1
one or more magnetic field sensing elements configured to generate a magnetic field signal indicative of a current through a conductor
Data Source
AI summary
Systems and methods described herein provide a current sensor having fault detection circuitry configured to detect over-current and/or current faults corresponding to current through a conductor being greater than a predetermined level. The current sensor can include a shared signal path, a main signal path, and a fault detection signal path to perform both fault detection and current detection signal processing. The current sensor can include one or more magnetic field sensing elements configured to generate a magnetic field signal indicative of the current through the conductor, an analog-to-digital converter (ADC) configured to receive the magnetic field signal and convert the magnetic field signal into a digital signal, and a fault detector responsive to the digital signal to generate a fault signal indicative of the current through the conductor being greater than a predetermined level.