NAND Flash Memory Voltage Generator with Period-Based Voltage Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing NAND flash memory devices face challenges in efficiently generating and managing operating voltages for various operations, leading to inefficiencies and potential reliability issues.
Innovation Solution
A memory device with a voltage generator that utilizes a first and second external voltage to generate operating voltages through a first and second period, incorporating charge pump circuits and a regulator to produce a range of voltages for different operations, including a low breakdown voltage transistor for control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single voltage generator circuit is used to generate all operating voltages, then device complexity is reduced, but voltage generation stability and reliability deteriorate
Solution Approach 1:
The voltage generator is divided into two independent circuits: a first voltage generator circuit that generates voltages during a first operation period, and a second voltage generator circuit that generates voltages during a second operation period. This segmentation allows each circuit to be optimized for specific operational requirements, improving overall reliability while maintaining manageable complexity.
2Adaptability or versatility
If voltage generation switches between different external voltages, then voltage generation flexibility improves, but control complexity increases
Solution Approach 1:
The voltage generator employs dynamic switching between different external voltages (first external voltage and second external voltage) based on operational periods. The control circuit dynamically selects which external voltage to use, enabling flexible adaptation to different operational requirements while managing control complexity through systematic period-based switching.
3Power
If charge pump circuits are used for voltage multiplication, then voltage generation capability improves, but energy consumption increases
Solution Approach 1:
The charge pump circuits operate in periodic intervals, being activated only during specific operation periods when voltage multiplication is required. By confining charge pump operation to discrete time windows rather than continuous operation, the system achieves necessary voltage generation capability while significantly reducing overall energy consumption.
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
Enhances the efficiency and reliability of NAND flash memory operations by providing stable and optimized voltage generation, improving data storage and retrieval processes.
Implementation Method 1
a charge pump circuit to generate a boosted voltage
Implementation Method 2
a regulator to adjust the voltage level to generate a voltage
Data Source
AI summary
According to one embodiment, a memory device includes: a memory cell array including a plurality of memory cells; and a voltage generator that is supplied with a first external voltage and a second external voltage higher than the first external voltage and generates an operating voltage of the memory cell array. An operation mode of the voltage generator at a time of generating a first voltage value of the operating voltage includes a first mode including a first period and a second period after the first period, and the first mode of generating the operating voltage using the first external voltage in the first period and using the second external voltage in the second period.