Parallel Current Ranging Circuit for Continuous Wide-Range Measurement
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Solution Overview
Problem
Existing current measurement systems face discontinuities and errors at range boundaries due to real-time switching, struggle to provide accurate measurements across a wide range of currents, and have difficulty measuring small changes in large currents without sacrificing accuracy or resolution.
Innovation Solution
A current measurement system utilizing a plurality of parallel sensing circuits, each triggered by a common buffer reaching a respective threshold, with a processor combining data to determine current, and incorporating a virtual ground buffer and feedback loops for continuous and accurate measurements across multiple ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If real-time switching is used to select appropriate resistors for different current ranges, then measurement range is extended, but measurement continuity and accuracy deteriorate due to discontinuities and errors at range boundaries
Solution Approach 1:
The measurement system is divided into multiple parallel sensing circuits, each dedicated to a specific current range. Each circuit contains measurement resistors configured for its designated range, eliminating the need for switching between ranges. The system segments the measurement function across parallel independent circuits that simultaneously monitor different current magnitudes.
Solution Approach 2:
The buffer circuit serves multiple functions simultaneously: it drives the common node for all sensing circuits, provides virtual ground to maintain measurement accuracy, and enables all sensing circuits to operate across their respective ranges without interruption. This multi-functional design allows the system to maintain measurement capability across the full current spectrum without switching.
2Adaptability or versatility
If switching between discrete measurement ranges is implemented, then wide current measurement capability is achieved, but measurement continuity deteriorates due to momentary interruptions
Solution Approach 1:
All parallel sensing circuits remain continuously active and connected to the common node simultaneously. Each circuit continuously measures its designated current range without interruption. The system maintains continuous measurement action across all ranges by having all sensing circuits permanently connected and operational, eliminating any gaps or interruptions in the measurement process.
3Adaptability or versatility
If multiple measurement resistors are used in series or parallel configurations, then current ranging capability is improved, but device complexity increases due to switching requirements and circuit design complications
Solution Approach 1:
The system segments the current measurement function into multiple parallel sensing circuits, each handling a specific current range with its own measurement resistors. This segmentation eliminates the need for complex switching mechanisms that would be required in series or parallel resistor configurations, as each circuit independently measures its designated range without requiring reconfiguration.
Solution Approach 2:
The buffer circuit acts as an intermediary element that connects all parallel sensing circuits to a common node. This buffer simplifies the overall circuit design by providing a centralized connection point that all sensing circuits share, eliminating the need for complex interconnections and switching arrangements between different resistor configurations.
4Measurement precision
If guarding is implemented in low current ranges, then measurement accuracy is improved, but device complexity and error sources increase
Solution Approach 1:
Each parallel sensing circuit is designed with local quality optimized for its specific current range. Low current sensing circuits incorporate appropriate guarding and high-impedance design elements tailored to their range, while high current circuits use different optimization strategies. This localized optimization allows each circuit to achieve high accuracy for its designated range without requiring the entire system to accommodate all complexity requirements.
Data Source
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AI summary
A current measurement system, comprising a plurality of parallel sensing circuits, each sensing circuit configured to measure a respective range of voltage corresponding to a current through a load, wherein each sensing circuit is triggered to initiate measurement of a voltage across the load in response to a buffer current through a common buffer reaching a respective threshold, a buffer circuit for inputting a virtual ground voltage or a virtual ground current to the load and to the plurality of parallel sensing circuits, the virtual ground voltage corresponding to the voltage across the load or the current through the load, and a processor coupled to the plurality of parallel sensing circuits, wherein the processor is configured to combine data representing voltage measurements from the plurality of parallel sensing circuits to determine the current through the load.