0/180° Phase Detector With Extended Corrective Pulses

Solution Overview

Problem

Conventional phase detectors, especially at high frequencies, fail to generate corrective pulses effectively due to rise and fall time limitations, leading to incomplete phase correction between reference and feedback signals in applications like motor control and communications.

Innovation Solution

A system with up-pulse and down-pulse generators that modulate pulse duration proportionally to the phase difference between a reference signal and a phase-shifted signal, using identical circuits with inverted inputs to generate pulses that extend in duration based on phase lag or lead, thereby correcting phase errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional phase detectors use linear multiplier or bang-bang configuration, then phase error detection is achieved, but at high frequencies the corrective pulses disappear due to rise and fall time limitations

Engineering Contradiction:

Improvephase correction effectivenessVSAvoidoperating frequency

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent implements dynamic pulse width modulation where the pulse width is continuously adjusted based on the phase error magnitude. The phase detector generates variable-width pulses whose duration is proportional to the phase difference between reference and feedback signals, allowing the system to adapt to different frequency conditions and maintain effective phase correction at high operating frequencies where conventional fixed-width pulses would fail

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the temporal parameter of the corrective pulses by modulating their width dynamically. Instead of using fixed-width pulses that disappear at high frequencies, the system varies the pulse width parameter in proportion to the detected phase error, ensuring that corrective action remains effective across a wide frequency range including high-frequency operations

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If phase error is small, then the system approaches zero phase shift, but the up and down pulses become narrower and disappear at high frequencies

Engineering Contradiction:

Improvephase error detection accuracyVSAvoidpulse width

Core Design Contradiction:

Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent implements dynamic pulse width modulation where the pulse width is continuously adjusted based on the phase error magnitude. The phase detector generates variable-width pulses whose duration is proportional to the phase difference between reference and feedback signals, allowing the system to adapt to different frequency conditions and maintain effective phase correction at high operating frequencies where conventional fixed-width pulses would fail

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs preliminary detection of the phase error magnitude and uses this information to pre-determine the appropriate pulse width before generating the corrective pulse. This preliminary measurement allows the system to generate adequately wide pulses even when the phase error is small, ensuring that the corrective action is sufficient to be detected and processed by subsequent circuitry

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS7885361B2Method and apparatus for 0/180 degree phase detector

Publication Date: 2011.02.08 TERADYNE INC

AI summary

An embodiment of the present invention provides a system for detecting a phase-shifted signal at high frequencies in data and clock recovery circuitry. An up-pulse generator, in one embodiment, provides output pulses having a duration exceeding the duration of input pulses upon detection of a phase-shifted signal leading the reference signal. A down-pulse generator provides output pulses having a duration exceeding the duration of input pulses upon detection of a phase-shifted signal lagging the reference signal.