Shared On-Chip Current Sensing for Low-Voltage IC Subcircuits
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Solution Overview
Problem
Current integrated circuit (IC) designs that measure load currents consume significant substrate area and power due to the use of multiple transducers and analog-to-digital converters (ADCs), which is problematic for portable devices powered by batteries.
Innovation Solution
The IC design incorporates a single transducer and ADC with a multiplexer to share these components among multiple current sensing circuits, reducing substrate area and power consumption while maintaining accurate current measurement and control of subcircuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple transducers and ADCs are used for current sensing in each subcircuit, then measurement precision is improved, but substrate area and power consumption increase
Solution Approach 1:
The patent merges multiple current sensing circuits into a single shared transducer and ADC resource. The current sensing circuit includes a transducer that converts current to voltage, and an ADC that converts the voltage to digital data. Multiple subcircuits share these components through time-multiplexed operation, eliminating the need for separate transducers and ADCs for each subcircuit, thereby reducing substrate area while maintaining measurement precision.
Solution Approach 2:
The transducer and ADC are designed as universal components that can serve multiple subcircuits. The current sensing circuit is configured to selectively measure current from different subcircuits by controlling the switching element, allowing a single transducer and ADC to perform the measurement function for multiple subcircuits sequentially, thus reducing the total number of components required.
2Measurement precision
If multiple transducers and ADCs are used for current sensing in each subcircuit, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent merges multiple current sensing circuits into a single shared transducer and ADC resource. The current sensing circuit includes a transducer that converts current to voltage, and an ADC that converts the voltage to digital data. Multiple subcircuits share these components through time-multiplexed operation, eliminating the need for separate transducers and ADCs for each subcircuit, thereby reducing substrate area while maintaining measurement precision.
Solution Approach 2:
The transducer and ADC are designed as universal components that can serve multiple subcircuits. The current sensing circuit is configured to selectively measure current from different subcircuits by controlling the switching element, allowing a single transducer and ADC to perform the measurement function for multiple subcircuits sequentially, thus reducing the total number of components required.
3Device complexity
If current sensing circuits are integrated on-chip, then device complexity is reduced, but measurement precision may deteriorate
Solution Approach 1:
The current sensing circuit is segmented into functional blocks: a transducer for current-to-voltage conversion, an ADC for voltage-to-digital conversion, and a control system for managing multiple subcircuits. This segmentation allows for precise measurement while maintaining compact integration. Each segment is optimized for its specific function, ensuring measurement precision is not compromised by integration.
Solution Approach 2:
The patent introduces a switching element as an intermediary between the current sensing circuit and multiple subcircuits. This switch enables selective connection of different subcircuits to the shared transducer and ADC, allowing precise measurement of individual subcircuit currents while maintaining low overall device complexity through resource sharing.
Data Source
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AI summary
An on-chip low-voltage current sensing circuit for measuring current in an integrated circuit (IC). In one embodiment, an IC formed on a substrate, which includes a plurality of subcircuits, and a plurality of sensing circuits coupled to the plurality of subcircuits, respectively. The plurality of sensing circuits are configured to generate a plurality of currents, respectively, that are proportional to a plurality of load currents, respectively, consumed by the plurality of subcircuits, respectively, during operation thereof. A circuit is coupled to the plurality of sensing circuits and configured to generate a signal based on an aggregate of the plurality of currents.