Memory Device Channel Initialization and Local Line Floating
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Solution Overview
Problem
Memory devices face errors during program operations, which can lead to unreliable read operations and decreased data reliability due to voltage fluctuations and channel initialization issues.
Innovation Solution
A memory device with a voltage generator, pass switches, and a logic circuit that initializes channels and floats local lines after program operations, ensuring that global word lines are maintained at a positive voltage higher than ground to prevent voltage drops and maintain data reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If channels are initialized during program operations, then data reliability is improved, but voltage fluctuations occur causing errors
Solution Approach 1:
The patent applies preliminary action by initializing channels and floating local lines before program operations complete. The logic circuit performs channel initialization in advance during the program operation sequence, and floats local lines beforehand to prevent voltage drops. This preliminary preparation ensures channels are ready for reliable data storage while preventing the voltage fluctuations that would otherwise cause errors during subsequent read operations.
Solution Approach 2:
The patent implements beforehand cushioning by maintaining global word lines at a positive voltage higher than ground potential. This voltage cushion prevents voltage drops and fluctuations from affecting channel stability. The logic circuit controls the voltage generator to sustain elevated voltages on global word lines, creating a protective voltage margin that cushions against harmful voltage variations during program and read operations.
2Power
If local lines are connected to global lines during program operations, then program voltage is supplied, but voltage drops occur after operations
Solution Approach 1:
The patent applies preliminary action by floating local lines before program operations complete. The logic circuit controls pass switches to disconnect (float) local lines from global lines in advance, preventing voltage drops that would occur if local lines remained connected. This preliminary disconnection ensures voltage stability is maintained after program operations while still allowing program voltage to be supplied during the actual programming phase.
3Reliability
If global word lines are maintained at positive voltage, then voltage drops are prevented, but energy consumption increases
Solution Approach 1:
The patent applies preliminary action by floating local lines during program operations. This preliminary disconnection isolates local lines from global word lines, allowing the logic circuit to reduce or eliminate voltage on global word lines during programming. The local lines are floated in advance, enabling energy reduction while maintaining channel integrity. When read operations occur, global word lines are reactivated at appropriate voltages, balancing energy consumption with reliability requirements.
Data Source
AI summary
The memory device includes a memory block, a voltage generator, a pass switch group connecting or blocking the global lines and the local lines to each other or from each other in response to a block selection voltage, a decoder, and a logic circuit configured to control the decoder and the voltage generator so that the local lines are floated after initializing a channel of the strings and a voltage of the global lines is lower than a voltage of the global lines when initializing the channel of the strings, when a program operation of selected memory cells included in a selected page of the memory block is completed, the channels of the strings are initialized and the local lines are floated.