Duty Cycle Correction Using Moving Sum Threshold Control

Solution Overview

Problem

Conventional duty cycle correction apparatuses require complex control circuits to maintain a constant 50% duty cycle, leading to increased current consumption and complexity.

Innovation Solution

An apparatus and method that corrects a distorted duty cycle using a moving sum unit, comparison unit, mean value calculation unit, and threshold voltage control unit to adjust the duty cycle of a square-wave signal to 50% by performing moving sum calculations, comparing signals with a threshold voltage, and controlling the threshold voltage based on calculated mean values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional apparatus for duty cycle correction is used to maintain a constant 50% duty cycle, then the duty cycle correction function is achieved, but the control circuit becomes complicated and current consumption increases

Engineering Contradiction:

Improveduty cycle constancyVSAvoidcontrol circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The apparatus uses the distorted clock signal itself as the input to the moving sum unit, eliminating the need for external reference signals. The system self-corrects by processing its own input signal through moving sum calculation, comparison, and threshold adjustment, thereby reducing external circuit requirements and simplifying the overall control circuit while maintaining duty cycle constancy

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The apparatus dynamically adjusts the threshold voltage parameter based on the mean value of the comparison output to correct the duty cycle. By changing the threshold parameter adaptively rather than using fixed complex control logic, the system achieves reliable duty cycle correction with simpler circuitry and reduced current consumption

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a conventional apparatus for duty cycle correction is used to maintain a constant 50% duty cycle, then the duty cycle correction function is achieved, but current consumption increases

Engineering Contradiction:

Improveduty cycle constancyVSAvoidcurrent consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The apparatus uses the distorted clock signal itself as the input to the moving sum unit, eliminating the need for external reference signals. The system self-corrects by processing its own input signal through moving sum calculation, comparison, and threshold adjustment, thereby reducing external circuit requirements and simplifying the overall control circuit while maintaining duty cycle constancy

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The apparatus dynamically adjusts the threshold voltage parameter based on the mean value of the comparison output to correct the duty cycle. By changing the threshold parameter adaptively rather than using fixed complex control logic, the system achieves reliable duty cycle correction with simpler circuitry and reduced current consumption

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7920004B2Apparatus and method for duty cycle correction

Publication Date: 2011.04.05 INTELLECTUAL DISCOVERY CO LTD

AI summary

There is provided an apparatus for duty cycle correction. The apparatus for duty cycle correction comprises a moving sum unit performing a moving sum calculation with respect to the square-wave signal and outputting the moving sum signal subjected to moving sum calculation, a comparison unit comparing the moving sum signal with a predetermined threshold voltage, outputting a high signal or low signal, a mean value calculation unit calculating the mean value of an output signal outputted from the comparison unit, the output signal being included in a section having a period integer times greater than that of the square-wave signal, and a threshold voltage control unit comparing the mean value with a middle value, increasing the threshold voltage when the mean value is greater than the middle value, and decreasing the threshold voltage when the mean value is less than the middle value.