IR-drop Reference Circuit Using Quiescent Voltage Sampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for monitoring IR-drop and supply noise in semiconductor integrated circuits require external reference signals and additional lines, which are not desirable due to area and power constraints, and do not accurately represent the supply voltage as it is affected by IR-drop.
Innovation Solution
An integrated circuit with a sampling unit, storage unit, and comparing unit that stores a supply voltage value during a quiescent state as a clean reference, allowing for comparison with a voltage value during an active state, eliminating the need for external reference signals and enabling accurate monitoring of IR-drop and supply noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external reference signals and additional lines are used for monitoring, then measurement accuracy is improved, but chip area and power consumption increase
Solution Approach 1:
The monitoring circuit uses the local supply voltage itself as the reference signal, eliminating the need for external reference lines. The circuit samples the supply voltage during quiescent states and stores these values for comparison during active states, allowing the system to self-monitor without additional external infrastructure.
Solution Approach 2:
The invention extracts and stores clean reference voltage values during quiescent states (when no significant current flows), separating these reference values from the noisy active supply voltage. This extraction allows the reference signal to be obtained without requiring separate external reference lines throughout the chip.
2Stability of the object's composition
If external reference signals are supplied through additional lines, then reference voltage stability is improved, but device complexity and pin requirements increase
Solution Approach 1:
The circuit generates its own reference signal by sampling the local supply voltage during quiescent states, eliminating dependence on external reference lines and pins. The stored reference values are later used for comparison during active operation, providing stable reference without additional complexity.
3Area of stationary object
If local supply voltage is used as reference during operation, then chip area is reduced, but measurement accuracy deteriorates due to IR-drop
Solution Approach 1:
The circuit performs preliminary sampling of the supply voltage during quiescent states (when IR-drop is minimal) to establish clean reference values before they are needed during active operation. These pre-stored reference values are then used for accurate comparison during high-current modes, avoiding the IR-drop contamination that would occur if sampling happened during operation.
Data Source
AI summary
Apparatus and method for IR-drop and supply noise measurements in electronic circuits. A first voltage at a point of interest in the circuit is sampled and stored during a quiescent mode of the circuit the voltage is to be measured in. Subsequently, the circuit is brought in an operating mode and a second voltage is sampled and held at the same point of interest. The first and the second voltage are compared and a corresponding voltage signal is passed to a system output.