Resistive Memory Array Sensing Without Selection Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current resistive change element arrays face challenges in scaling and increasing cell density due to the physical limitations of in situ selection devices, which also lead to issues with sneak current and leakage current, affecting the accuracy of determining resistive states without in situ selection devices within each cell.
Innovation Solution
A circuit and method that utilize a current source and sense circuit with a field effect transistor and differential amplifier to determine resistive states of resistive change elements without in situ selection devices, reducing sneak current by controlling current flow through a metal oxide semiconductor field effect transistor or carbon nanotube field effect transistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If in situ selection devices are used within each resistive change element cell, then selection and control of individual cells is enabled, but device complexity increases and cell density scaling is limited due to physical dimensions of selection devices
Solution Approach 1:
The patent removes the in situ selection device from within each resistive change element cell, extracting the selection function entirely. This allows cells to consist only of the resistive change element itself, reducing cell complexity and enabling higher density scaling while selection is handled by external circuitry (sense amplifier and current source) operating on the entire array or subsets thereof
2Ease of operation
If in situ selection devices are used within each cell, then individual cell access is achieved, but sneak current and leakage current increase affecting measurement accuracy
Solution Approach 1:
The patent acknowledges that removing in situ selection devices creates sneak current paths through unselected cells, but converts this potential harm into a manageable condition by using sense amplifiers with hysteresis and configurable current sources that can distinguish desired signal from leakage background, effectively using the leakage-aware design to achieve accurate measurements despite the presence of sneak currents
3Productivity
If in situ selection devices are removed from cells, then cell density and scalability increase, but control over current flow to prevent sneak current becomes more difficult
Solution Approach 1:
The patent implements a universal current source and sense amplifier architecture that can be configured to work with entire arrays or subsets of cells without requiring individual cell-level control devices. The sense amplifier with hysteresis provides multi-functional operation (reading, distinguishing states, rejecting noise) that simplifies the overall control structure while enabling high cell density
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
Enables accurate determination of resistive states in resistive change element arrays without in situ selection devices, reducing the impact of sneak current and allowing for higher cell density and scalability by controlling current flow effectively.
Implementation Method 1
A sense circuit includes a field effect transistor dimensioned for determining a resistive state of a resistive change element
Implementation Method 2
determining the resistive state of the resistive change element
Data Source
AI summary
Devices and methods for determining resistive states of resistive change elements in resistive change element arrays are disclosed. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements by sensing current flow. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements without the need for in situ selection devices or other current controlling devices. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can reduce the impact of sneak current when determining resistive states of resistive change elements.