High-Impedance Differential Current Sensing for Stable Sense Nodes
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Solution Overview
Problem
Current-sensing circuits in computing devices face challenges such as high power consumption due to low input impedance, voltage degradation at sense nodes, and limited availability of solder bumps for sensing, which affect precision and efficiency.
Innovation Solution
High-impedance current-sensing circuits are designed with first and second amplifiers coupled to sense nodes, using current mirrors and resistors to minimize current draw and circuit size, allowing for precise current measurement with reduced power consumption and voltage reference options.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional current-sensing circuits are used, then current measurement function is achieved, but power consumption is high due to low input impedance
Solution Approach 1:
The patent introduces high-impedance buffer amplifiers as intermediary components between the sense nodes and the current-sensing circuitry. These buffers act as mediators that isolate the sense nodes from the loading effects of the sensing circuit, maintaining high input impedance to minimize current draw while preserving the voltage signal for accurate current measurement.
Solution Approach 2:
The patent fundamentally changes the input impedance parameter of the sensing circuit from low (conventional) to high (novel). By designing the sensing circuit with high input impedance characteristics, the circuit draws minimal current from the sense nodes while maintaining the ability to accurately measure voltage drops for current determination.
2Measurement precision
If conventional current-sensing circuits are used, then current measurement is achieved, but voltage degradation occurs at sense nodes
Solution Approach 1:
High-impedance buffer amplifiers are introduced as intermediary components that isolate the sense nodes from the loading effects of the sensing circuitry. These buffers prevent voltage degradation by minimizing the current drawn from the sense nodes, thereby maintaining voltage stability without affecting the measured signal.
3Adaptability or versatility
If more sense nodes are added for multi-domain sensing, then sensing capability is improved, but availability of solder bumps is exceeded
Solution Approach 1:
The patent makes the sensing circuit universal by designing it to operate across multiple voltage domains (e.g., 1.0V, 1.2V, 1.5V, 1.8V, 3.3V) through high-impedance buffering. This multi-functionality allows a single sensing circuit configuration to serve multiple voltage domains without requiring separate sense nodes for each domain, reducing the total number of solder bumps needed.
Solution Approach 2:
The patent uses partial sensing action by measuring voltage drops across selected sense nodes rather than requiring dedicated sense nodes for every voltage domain. The high-impedance buffering allows the circuit to selectively monitor multiple domains using fewer physical connection points, avoiding the need for excessive solder bumps.
Data Source
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AI summary
Embodiments herein relate to a high-impedance current-sensing circuit. In one approach, the circuit includes first and second amplifiers which are coupled to first and second sense nodes, respectively, of a load to be monitored, one or more current mirrors to mirror a current to a voltage output node, and first and second resistors coupled to an input and output, respectively, of the one or more current mirrors. A voltage at the voltage output node is based on a current between the first and second sense nodes, and can be used for various purposes such as limiting the current through the load.