Clock Duty Cycle Correction With Dynamic Resolution Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices face challenges in accurate data communication due to phase skew between clock signals and data, which is exacerbated by process variations and transistor skew, leading to reduced data valid windows and impaired communication efficiency.
Innovation Solution
A duty cycle correction device and method that includes a duty cycle correction circuit and a duty cycle control circuit, which receive an input clock signal, correct its duty cycle using a duty cycle control signal and a duty cycle resolution control signal, and activate the resolution control signal when a threshold count is reached, allowing for fine-tuned correction of the clock signal's resolution to synchronize data and clock signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If duty cycle correction is performed with fixed resolution, then correction speed is maintained, but correction precision is insufficient for small duty cycle errors
Solution Approach 1:
The patent implements dynamic resolution switching in the duty cycle correction circuit. The correction resolution is adjusted based on the magnitude of the detected duty cycle error: high resolution mode is activated when error is small (requiring precise correction), while low resolution mode is used when error is large (enabling faster correction). This dynamic adaptation resolves the contradiction by making the correction precision variable rather than fixed.
Solution Approach 2:
The patent changes the resolution parameter of the duty cycle correction circuit based on the error magnitude. A resolution control signal switches between different correction resolutions (e.g., first resolution for large errors, second resolution for small errors). This parameter change allows the system to achieve high precision when needed while maintaining faster operation during coarse correction phases.
2Measurement precision
If high resolution correction is applied continuously, then correction precision is maximized, but correction time increases
Solution Approach 1:
The patent employs periodic switching between different correction resolutions based on the correction progress. The system starts with low resolution for rapid initial correction, then transitions to high resolution when the duty cycle error becomes small. This periodic adjustment of correction intensity optimizes the trade-off between speed and precision throughout the correction process.
Solution Approach 2:
The patent applies partial correction action by using different resolution levels at different stages. Instead of continuously applying maximum resolution correction, the system uses appropriate correction intensity for each phase: aggressive low-resolution correction for large errors, and refined high-resolution correction for small residual errors. This prevents unnecessary time loss while maintaining precision when required.
3Reliability
If duty cycle correction is performed without adaptive resolution control, then circuit operation is simple, but data communication accuracy deteriorates under process variation
Solution Approach 1:
The patent implements a feedback mechanism where the duty cycle error is continuously detected and used to control the correction resolution. The error detection circuit monitors the duty cycle deviation, and this information feeds back to the resolution control logic, which adjusts the correction resolution accordingly. This closed-loop feedback ensures high communication accuracy by adapting to actual error conditions while managing circuit complexity through systematic control.
Solution Approach 2:
The patent makes the correction system dynamic by enabling the resolution parameter to change based on real-time error detection. The correction circuit transitions from static fixed-resolution operation to dynamic adaptive-resolution operation, where the resolution level is determined by the magnitude of the detected duty cycle error. This dynamic behavior improves reliability under process variation while keeping the control mechanism systematic.
Data Source
AI summary
A duty cycle correction device includes a duty cycle correction circuit and a duty cycle control circuit. The duty cycle correction circuit corrects a duty cycle of an input dock signal based on a duty cycle control signal and a duty cycle resolution control signal to generate an output dock signal. The duty cycle control circuit generates the duty cycle control signal by detecting a duty cycle of the output clock signal, generates a duty cycle correction completion signal when duty cycle correction is completed, and recorrects the duty cycle of the input clock signal by activating the duty cycle resolution control signal when the duty cycle correction completion signal is activated at an earlier timing than a reference time.