Memory Output Driving Circuit With Pulse Compensation for Faster Slew Rate
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Solution Overview
Problem
The slew rate of output signals from high-speed output ports in DRAMs is limited by logic device rates, hindering the increase in transmission rates and affecting signal quality.
Innovation Solution
An output driving circuit with a signal input terminal for positive and negative input signals, pull-up and pull-down output units, compensation units, and a pulse signal generation circuit that generates a pulse signal to control the compensation units, increasing the slew rate by adding additional current during signal conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the logic device rate in the memory process is increased to improve transmission rate, then the transmission rate increases, but the slew rate of the output signal cannot be improved due to logic device limitations
Solution Approach 1:
The patent applies preliminary action by generating a pulse signal in advance that activates the compensation unit before the main signal transition occurs. This pulse signal, generated by the pulse signal generation circuit, prepares the compensation transistors to provide additional current during the critical signal transition period, thereby improving the slew rate without being constrained by the logic device operating rate.
2Reliability
If the slew rate of the output signal is increased to improve signal quality, then the signal quality improves, but the logic device rate becomes a limiting factor
Solution Approach 1:
The patent introduces an intermediary element - the compensation unit controlled by the pulse signal generation circuit - that acts as a mediator between the logic device output and the final signal. This compensation unit provides additional current during signal transitions, improving signal quality and slew rate without requiring the logic devices themselves to operate at higher rates.
3Speed
If additional compensation units are added to increase the slew rate, then the slew rate improves, but the device complexity increases
Solution Approach 1:
The patent employs periodic action by using a pulse signal that is generated periodically or on-demand based on signal transition detection. The pulse signal generation circuit activates the compensation units only during the specific periods when signal transitions occur, rather than keeping them continuously active. This approach improves the slew rate when needed while minimizing the overall circuit complexity and power consumption.
Data Source
AI summary
The present application provides an output driving circuit and a memory. The output driving circuit includes: a signal input terminal inputting a positive input signal and a negative input signal complementary to each other; a pull-up output unit and a pull-down output unit connected to the signal input terminal, the positive input signal acting as an input signal of the pull-up output unit, and the negative input signal acting as an input signal of the pull-down output unit; at least one compensation unit connected in parallel with the pull-up or pull-down output unit; at least one pulse signal generation circuit, and generating a pulse signal, the pulse signal acting as a control signal of the compensation unit; and a signal output terminal connected to an output terminal of the pull-up output unit, an output terminal of the pull-down output unit and an output terminal of the compensation unit.