Semiconductor Memory Device Overdriving Charge Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor memory devices using overdriving and discharge driving methods, a significant amount of power is wasted as charge is discarded by connecting the pull-up power line to ground voltage, leading to inefficient energy utilization during frequent bit line sensing and amplification operations.
Innovation Solution
A semiconductor memory device with a bit line sense amplification unit and a driving control unit that supplies an overdriving voltage during the overdriving period and uses the power line voltage to charge internal voltage lines during the discharge driving period, allowing the power line to be coupled to a core voltage line in a discharge period, thereby reutilizing the overdriving charge and reducing current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the external power supply voltage VDD is used as the overdriving voltage for the pull-up power line, then data of many cells can be stably amplified at a time with adequate current, but the voltage level of the pull-up power line takes a long time to return to the target core voltage level after the overdriving operation
Solution Approach 1:
The patent extracts the excess voltage from the pull-up power line after overdriving and redirects it to charge internal voltage lines. By separating the overdriving function from the voltage recovery function, the system achieves rapid voltage return while maintaining amplification stability during overdrive.
Solution Approach 2:
Instead of discarding the excess voltage on the pull-up power line after overdriving, the patent recovers this energy by coupling the pull-up power line to internal voltage lines, transferring the excess charge to charge them. This recovers what would otherwise be wasted energy and accelerates voltage recovery.
2Speed
If the pull-up power line is connected to ground voltage to rapidly discharge it after overdriving, then the voltage level returns quickly to the target core voltage, but a significant amount of power is wasted as the overdriving charge is discarded
Solution Approach 1:
The patent converts the harmful effect of excess voltage (which needs to be discharged) into a beneficial resource by using it to charge internal voltage lines. The excess charge that would be wasted is instead utilized to supply power to other parts of the system, simultaneously achieving rapid voltage recovery and energy conservation.
Solution Approach 2:
Rather than discarding the charge through ground connection, the patent recovers the energy by coupling the pull-up power line to internal voltage lines during the discharge period, transferring the excess charge to where it is needed.
3Productivity
If the pull-up power line voltage is rapidly discharged to the target core voltage level after overdriving, then subsequent sensing operations can proceed timely, but the frequent overdriving and discharge operations lead to high current consumption
Solution Approach 1:
The patent merges the discharge function with the charging function by coupling the pull-up power line to internal voltage lines. The same coupling mechanism that enables rapid voltage recovery also captures and utilizes the excess energy, combining two functions into one operation to reduce overall current consumption.
Solution Approach 2:
The system serves itself by using the excess charge from the pull-up power line to charge internal voltage lines that need power. The overdriving charge essentially pays for its own recovery and simultaneously provides energy to other parts of the system, reducing the need for additional power supply.
Data Source
AI summary
A semiconductor memory device includes a bit line sense amplification unit configured to sense/amplify data loaded on a bit line, and a driving control unit configured to supply a power line of the bit line sense amplification unit with an overdriving voltage in an overdriving period and supply an internal voltage line with a voltage of the power line of the bit line sense amplification unit in a discharge driving period.