Nonvolatile Memory Block Unselecting Circuit Area Reduction
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Solution Overview
Problem
The existing nonvolatile memory devices have a large peripheral circuit area, particularly the row decoder, which increases costs and complexity due to the need to apply off-voltages to all string selection lines for unselected memory blocks, leading to inefficiencies in power management and increased size.
Innovation Solution
The nonvolatile memory device design includes a block unselecting circuit that connects only to specific string selection lines of an unselected memory block, allowing for the application of off-voltages to only those lines, reducing the size and complexity of the row decoder and minimizing unnecessary power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the block unselecting circuit connects to all string selection lines to apply off-voltages, then memory block unselection is reliable, but the peripheral circuit area and device complexity increase
Solution Approach 1:
The patent segments the string selection lines into two groups: those connected to the block unselecting circuit and those not connected. This segmentation allows the circuit to apply off-voltages selectively only to specific lines, reducing the overall circuit area while maintaining reliable memory block unselection through the coordinated operation of the block selecting circuit and unselecting circuit.
Solution Approach 2:
The patent applies different connection configurations to different string selection lines based on their specific requirements. Some lines are connected to the block unselecting circuit while others are not, creating local quality variations that optimize both reliability and area efficiency for different portions of the memory structure.
2Adaptability or versatility
If the block unselecting circuit connects to all string selection lines, then complete voltage control is achieved, but the number of transistors and circuit complexity increase
Solution Approach 1:
The patent divides the voltage control function into two separate circuits: the block selecting circuit that controls multiple string selection lines, and the block unselecting circuit that controls only specific string selection lines. This segmentation reduces the transistor count and complexity of the overall row decoder while maintaining complete voltage control capability through coordinated operation of both circuits.
Solution Approach 2:
The patent applies partial action by having the block unselecting circuit connect only to specific string selection lines rather than all lines. This partial connection approach reduces circuit complexity while the block selecting circuit provides the necessary control for the remaining lines, achieving complete voltage control without excessive transistors.
3Reliability
If off-voltages are applied to all string selection lines, then memory block unselection is effective, but power consumption increases
Solution Approach 1:
The patent applies off-voltages locally only to specific string selection lines that require them for proper memory block unselection, rather than applying them to all lines. This local quality approach ensures effective unselection while minimizing unnecessary power consumption on lines that do not require off-voltages.
Solution Approach 2:
The patent uses partial action by applying off-voltages to only the necessary subset of string selection lines through the block unselecting circuit, rather than to all lines. This reduces overall power consumption while maintaining effective memory block unselection for the targeted lines.
Data Source
AI summary
A nonvolatile memory device includes a peripheral circuit region and a memory cell region. The peripheral circuit region includes a block selecting circuit, a block unselecting circuit, and a first metal pad. The memory cell region is vertically connected to the peripheral circuit region, and includes a first memory block and a second metal pad directly connected to the first metal pad. The block selecting circuit is connected with ground selection lines, word lines, and string selection lines, and provides corresponding driving voltages to the ground selection lines, the word lines, and the string selection lines in response to a block selection signal corresponding to the first memory block, respectively. The block unselecting circuit is connected only with specific string selection lines, and provides an off-voltage only to the specific string selection lines in response to a block un-selection signal.