Fuse Sensing Circuit Using Capacitor Discharge Rate Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional fuse sensing circuits face challenges with high power consumption, long read cycle times, and the need for additional pre-charge pins due to variations in process, voltage, and temperature, making them inefficient and cumbersome.
Innovation Solution
A fuse sensing circuit that determines the fuse state based on the discharging of capacitors, which reduces power consumption and eliminates the need for pre-charging by utilizing a circuit with capacitors that discharge current to a fuse unit cell, indicating the fuse state through a discharge rate difference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional fuse sensing circuits use back-to-back inverter latch sense scheme with pre-charge paths, then the fuse state can be detected, but power consumption becomes very high and read cycle time becomes very long
Solution Approach 1:
The patent changes the sensing mechanism from voltage comparison using inverters to current comparison using capacitor discharge rates. By changing the physical parameter being measured (from voltage to current discharge rate) and the operating principle (from static voltage comparison to dynamic discharge comparison), the circuit achieves accurate fuse state detection with significantly reduced power consumption, eliminating the need for continuous pre-charge paths
Solution Approach 2:
The patent uses periodic capacitor charging and discharging cycles to perform fuse state detection. The capacitors are charged during a pre-charge phase and then discharged during a sensing phase, creating periodic action that enables accurate measurement of fuse resistance through discharge rate comparison. This periodic operation reduces average power consumption compared to continuous operation of traditional sense circuits
2Measurement precision
If sense margin is increased to compensate for process variations, then detection accuracy improves, but current for PRCHG and SENSE inputs increases causing very high power consumption
Solution Approach 1:
The patent creates a copy of the sensing mechanism using matched capacitors (C1 and C2) with identical characteristics. By using matched components that are copies of each other, the circuit achieves high measurement precision through differential comparison while maintaining low power consumption. The matching eliminates the need for excessive sense margin, as any systematic variations affect both capacitors equally and cancel out in the differential measurement
3Reliability
If back-to-back inverter latch sense scheme is used, then fuse state can be detected, but additional pins (e.g., PRCHG pins) are required and read cycle time becomes very long
Solution Approach 1:
The patent merges the pre-charge and sensing functions into a single integrated capacitor discharge mechanism. The same capacitors used for sensing also serve the pre-charge function, eliminating the need for separate pre-charge paths and additional control pins. This consolidation reduces device complexity while maintaining reliable fuse state detection capability
Solution Approach 2:
The patent extracts and eliminates the unnecessary pre-charge pin requirement by redesigning the sensing mechanism. Instead of requiring external pre-charge pins to initialize the sense circuit, the invention uses internal capacitor discharge that naturally provides the necessary initialization, removing the complexity of additional pins and external pre-charge control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces power consumption, shortens read cycle times, and eliminates the requirement for additional pre-charge pins, resulting in a more efficient and accurate fuse state detection mechanism.
Implementation Method 1
first and second capacitors that are configured to charge and discharge based on the sense input terminal, wherein the first and second capacitors are further configured to discharge current to a fuse unit cell
Data Source
AI summary
A fuse sensing circuit is disclosed. Embodiments include: providing a sense input terminal; providing a sense output terminal; and providing first and second capacitors that are configured to charge and discharge based on the sense input terminal, wherein the first and second capacitors are further configured to discharge current to a fuse unit cell, and the sense output terminal is configured to indicate a fuse state of the fuse unit cell based on the discharging of the first and second capacitors. Embodiments include the indicated fuse state being based on a discharge rate difference between the discharging of the first capacitor and the discharging of the second capacitor.