3D NAND Read Current Peak Detection for Low-Power Threshold Sensing
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Solution Overview
Problem
Existing non-volatile memory technologies face challenges in accurately sensing the threshold voltage of memory cells while minimizing power consumption, particularly in 3D NAND stacked memory structures.
Innovation Solution
The proposed solution involves grouping memory cells into blocks and using a control means or controller to determine the amount of programmed cells based on electrical current consumption during a read operation, adjusting read parameters accordingly to identify threshold voltages above specific data states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional read operations are used to sense threshold voltage, then measurement can be performed, but power consumption is excessive
Solution Approach 1:
The patent applies preliminary action by performing a first read operation to detect open blocks before conducting the actual data read operation. This preliminary detection allows the system to identify blocks with erased memory cells that would consume excessive power, enabling subsequent optimization of the read operation to reduce power consumption while maintaining threshold voltage sensing accuracy.
Solution Approach 2:
The patent utilizes parameter changes by modifying read operation parameters based on the detection results from the first read operation. When open blocks are detected, the system adjusts read parameters such as bit line voltage levels or sensing thresholds to minimize power consumption during the actual data read, while still accurately sensing the threshold voltage of programmed memory cells.
2Use of energy by moving object
If read parameters are optimized for power reduction, then power consumption decreases, but threshold voltage sensing accuracy may be compromised
Solution Approach 1:
The patent implements feedback by using the results from the first read operation to inform and adjust parameters of the actual data read operation. The detection of open blocks provides feedback that enables the system to selectively optimize read parameters for power reduction only in blocks where it is safe to do so, while maintaining appropriate sensing parameters in blocks containing programmed data, thus preserving threshold voltage sensing accuracy.
Solution Approach 2:
The patent applies segmentation by treating different blocks differently based on their state. Blocks detected as open during the first read operation receive optimized low-power read parameters, while blocks containing programmed data maintain standard read parameters for accurate threshold voltage sensing. This segmented approach allows simultaneous power optimization and measurement precision maintenance across different memory blocks.
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 enhances the accuracy of threshold voltage sensing while reducing power consumption by optimizing read operations in non-volatile memory devices.
Implementation Method 1
determine an amount of the memory cells of one of the blocks that are programmed based on an electrical current consumed by the memory apparatus during a fourth period of time of a read operation
Data Source
AI summary
A memory apparatus and method of operation are provided. The apparatus includes memory cells configured to retain a threshold voltage and disposed in memory holes coupled to bit lines and grouped into blocks. A control means is configured to determine an amount of the memory cells of one of the blocks that are programmed based on an electrical current consumed by the memory apparatus during a fourth period of time of a read operation in which selected ones of the bit lines are ramped up to a bit line voltage. The control means adjusts at least one read parameter accordingly. The control means is also configured to utilize the adjusted at least one read parameter while reading the memory cells to determine if the memory cells have the threshold voltage above one or more read levels associated with each of the data states in the read operation.