Semiconductor Memory Data Output Timing With Variable Slew Rate
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Solution Overview
Problem
Existing semiconductor memory data output systems have a fixed slew rate and data output timing, limiting their applicability to high-speed operations and restricting their range due to the fixed resistor and transistor turn-on resistances.
Innovation Solution
Incorporating a bias generator and slew rate controller to dynamically control pull-up and pull-down slew rates, allowing for variable data output timing and slew rates, enabling the system to adapt to different operational requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed resistor and transistor structure is used to control slew rate, then the circuit structure is simple, but the slew rate cannot be varied and is fixed
Solution Approach 1:
The patent applies dynamics by replacing fixed resistors with dynamically controllable transistor switches that can adjust their resistance states. The slew rate controller dynamically changes the resistance of pull-up and pull-down networks by controlling transistor switching, enabling variable slew rates while maintaining a relatively simple circuit structure based on standard CMOS components.
Solution Approach 2:
The patent changes the resistance parameter of the pull-up and pull-down networks by controlling transistor gate voltages. By varying the gate voltages of control transistors, the effective resistance changes, which directly controls the slew rate. This allows the same circuit to operate at different slew rates without physical component changes.
2Adaptability or versatility
If fixed data output timing is used, then the timing control is simple, but the applicable range is excessively limited
Solution Approach 1:
The patent introduces dynamic timing control by using controllable delay elements and synchronized clock signals. The data output timing is adjusted dynamically based on system requirements by controlling the switching timing of output transistors, allowing the same apparatus to adapt to different timing requirements without adding complex external timing circuits.
3Speed
If resistor-based slew rate control is used, then the implementation is simple, but high speed operation is not applicable
Solution Approach 1:
The patent replaces passive resistor-based slew rate control with an active transistor-based control system. Instead of relying on fixed resistive networks, the invention uses voltage-controlled transistor switches that can rapidly change their conductance states, enabling much faster slew rate transitions and supporting high-speed operation while maintaining controllability.
Data Source
AI summary
An apparatus for outputting data of a semiconductor memory apparatus, which is capable of varying the slew rate and the data output timing, includes a bias generator that generates a bias having a level corresponding to a set value, a slew rate controller that controls a pull-up slew rate or a pull-down slew rate of input data on the basis of the bias generated by the bias generator, and a data outputting unit that outputs data on the basis of the slew rate controlled by the slew rate controller. Therefore, it is possible to satisfy various operational conditions without changing the structure of the circuit and to correspond rapidly and appropriately whit a change in the system, which enables the applied range of the products to be extended.