Output Driver Circuit Using Shared Pre-Drivers for Faster Pad Drive
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Solution Overview
Problem
Conventional output driver circuits in semiconductor memory devices require large MOS transistors due to series coupling, leading to increased circuit area and current consumption, which reduces operating speed.
Innovation Solution
The output driver circuit employs single MOS transistors and pre-driver units to generate driving signals, reducing circuit area and current consumption by eliminating series coupling and sharing pre-drivers across groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If MOS transistors are coupled in series to generate driving signals, then driving strength can be controlled, but operating speed is greatly reduced and circuit area increases
Solution Approach 1:
The patent divides the driving signal generation into multiple groups (first group, second group, etc.), where each group contains transistors that can be independently controlled. This segmentation allows the circuit to select appropriate driving strength without requiring all transistors to be in series, thereby maintaining operating speed while providing driving strength control.
Solution Approach 2:
The patent introduces dynamic control signals (first driving selection signal, second driving selection signal, etc.) that can dynamically select which transistors are activated in each group. This dynamic switching capability allows the circuit to adapt driving strength to actual needs without being locked into a fixed series configuration, thus improving operating speed.
2Reliability
If MOS transistors are coupled in series to ensure driving strength, then constant driving strength can be maintained, but circuit area increases
Solution Approach 1:
The patent designs transistor groups that can serve multiple functions - each group can provide different driving strength levels depending on the activation state. The same physical transistors can operate in different configurations (fully on, partially on, or off) to meet different driving requirements, eliminating the need for additional series-transistor chains and reducing circuit area.
Solution Approach 2:
The patent changes the operational parameters of transistor groups by controlling their activation states through selection signals. By adjusting which groups are active and their conduction states, the circuit can maintain consistent effective driving strength across varying conditions without requiring a large series chain of transistors, thus reducing circuit area.
3Power
If MOS transistors are coupled in series to control driving strength, then driving strength can be adjusted, but current consumption increases
Solution Approach 1:
The patent enables partial activation of transistor groups based on actual driving needs. Instead of always having all transistors in series and fully engaged, the circuit can activate only the necessary number and strength of transistor groups, avoiding excessive current consumption while still providing sufficient driving strength when needed.
Solution Approach 2:
The patent uses dynamic selection signals to control the activation state of different transistor groups in real-time. This dynamic control allows the circuit to optimize current consumption by activating only the minimum necessary driving strength for each operating condition, rather than maintaining a fixed high-current series configuration.
Data Source
AI summary
An output driver circuit includes a pre-driver unit and a first driving unit. The pre-driver unit is configured to generate a driving selection signal and a driving signal from a pre-driving signal in response to a group selection signal and a code signal. The first driving unit is configured to drive a data pad in response to the driving selection signal and the driving signal.