Semiconductor Memory Bit Line Equalization via Segmented Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor memory devices, the precharge time of bit lines is prolonged due to high integration load and parasitic capacitance, leading to increased cycle time and potential malfunctions during data readout, as existing methods fail to effectively equalize bit line potentials across long distances.
Innovation Solution
The semiconductor memory device incorporates a configuration with first and second amplifier circuits, bit lines, and equalizer circuits that short-circuit bit line pairs at both ends and far ends, using N-channel type MOS transistors to equalize and precharge bit line potentials, allowing precharging from both near and far ends of sense amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If bit lines are precharged from a single site, then device complexity is reduced, but precharge time increases due to long equalization distance
Solution Approach 1:
The bit line equalization function is segmented into multiple independent equalizer circuits distributed at different locations (first equalizer circuit near first amplifier, second equalizer circuit near second amplifier). This segmentation allows simultaneous equalization from multiple sites, reducing the maximum equalization distance and precharge time while maintaining manageable device complexity through modular circuit distribution.
Solution Approach 2:
The precharge operation transitions from a single-point (one-dimensional) equalization approach to a multi-point distributed equalization approach. By placing equalizer circuits at multiple locations along the bit line, the equalization process occurs simultaneously across different spatial dimensions, effectively reducing the time required for potential equalization across the entire bit line length.
2Area of stationary object
If bit lines are highly integrated, then device area is reduced, but precharge time increases due to increased load and parasitic capacitance
Solution Approach 1:
Different regions of the bit line are served by locally positioned equalizer circuits with appropriate sizing and positioning. The first equalizer circuit serves the region near the first amplifier while the second equalizer circuit serves the region near the second amplifier, allowing each equalizer to be optimized for its local segment's capacitive load, thereby reducing overall precharge time without increasing total device area.
3Device complexity
If bit line potential is not equalized, then precharge operation is simplified, but data readout malfunction occurs due to offset voltage
Solution Approach 1:
Multiple equalizer circuits are implemented to establish equipotential conditions across different bit line segments simultaneously. The first equalizer circuit equalizes potentials near the first amplifier and the second equalizer circuit equalizes potentials near the second amplifier, ensuring that all bit lines reach the same reference potential before readout operations, thereby eliminating offset voltages and preventing readout malfunctions.
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 configuration significantly shortens the precharge time by equalizing bit line potentials across the entire length, reducing cycle time and preventing data readout malfunctions by ensuring consistent bit line potentials, thus enhancing the speed and accuracy of memory operations.
Implementation Method 1
the precharge time of bit lines is prolonged due to high integration load and parasitic capacitance
Data Source
AI summary
A semiconductor device includes a first amplifier circuit, a second amplifier circuit, first and second bit lines coupled to the first amplifier circuit, third and fourth bit lines coupled to the second amplifier circuit, a first equalizer circuit being coupled to the first and second bit lines, and a second equalizer circuit being coupled between the second and third bit lines. The second equalizer circuit being closer to the second amplifier circuit than the first equalizer circuit, the first equalizer circuit being closer to the first amplifier circuit than the second equalizer circuit.