On-Chip Current Sensing via Power Distribution Network De-convolution
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Solution Overview
Problem
Existing methods for sensing current drawn by integrated circuit chips either incur additional costs through dedicated primary inputs or waste power due to the use of resistors for voltage drop measurement, failing to efficiently manage power consumption and prevent overheating or damage.
Innovation Solution
The system-on-chip (SOC) device employs current sensing logic to estimate current drawn from a power distribution network by measuring voltage and using de-convolution techniques based on the impulse response or transfer function of the network, eliminating the need for external sensors and resistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external current sensing is performed and current information is transferred via dedicated primary inputs, then current measurement capability is achieved, but chip cost increases
Solution Approach 1:
The patent extracts the current sensing function from external dedicated inputs and relocates it entirely within the chip by utilizing the existing power distribution network's voltage characteristics. The voltage sensor measures voltage drops across functional blocks, and the controller reconstructs current information internally, eliminating the need for external current sensors and dedicated primary inputs, thereby reducing chip cost while maintaining measurement capability.
Solution Approach 2:
The patent makes the power distribution network serve multiple functions: it continues to supply power to functional blocks while simultaneously acting as a sensing medium for current measurement. The existing voltage sensor, originally designed for voltage monitoring, is repurposed to measure voltage drops for current sensing, eliminating the need for separate dedicated sensing infrastructure and reducing overall system complexity and cost.
2Measurement precision
If a high precision resistor is built into the chip for voltage drop measurement, then current sensing accuracy is improved, but power consumption increases
Solution Approach 1:
The patent extracts the sensing function from a dedicated high precision resistor and distributes it across multiple functional blocks. Instead of using a single high precision resistor that would consume significant power, the system utilizes the inherent impedance characteristics of existing power distribution network elements, thereby maintaining sensing accuracy while dramatically reducing power consumption.
Solution Approach 2:
The patent introduces voltage sensors as intermediaries that indirectly measure current by detecting voltage drops across functional blocks. Rather than forcing current through a high precision resistor for measurement, the voltage sensors act as mediators that capture voltage information, which is then used by the controller to calculate current, thereby avoiding the power loss associated with high precision resistors.
3Device complexity
If voltage sensing is performed without de-convolution, then measurement simplicity is maintained, but current estimation accuracy deteriorates
Solution Approach 1:
The patent performs preliminary characterization of the power distribution network to establish the relationship between voltage drops and current draw. By pre-determining the electrical characteristics and impedance profiles of different functional blocks, the system prepares the necessary data structures and calibration information that enable accurate current estimation from voltage measurements without requiring complex real-time calculations, thus maintaining simplicity while improving accuracy.
Solution Approach 2:
The patent implements a feedback mechanism where the controller uses voltage sensor measurements, combined with stored impedance characteristics, to continuously estimate current consumption of individual functional blocks. This feedback loop allows the system to accurately track current draw by monitoring voltage drops and comparing them against known impedance values, thereby achieving high measurement precision while keeping the measurement process relatively simple through iterative refinement.
Data Source
AI summary
Systems, methods, and other embodiments are disclosed that are configured to provide on-chip current sensing by employing a power distribution network voltage de-convolution technique. A voltage signal on a voltage plane of a system-on-chip device is measured during operation of the system-on-chip device. The voltage signal derives from a power distribution network. The voltage signal is de-convolved, based at least in part on inverse convolution coefficients derived from the power distribution network, to recover a current signal being drawn by the system-on-chip device from the power distribution network.