Precision Phase Skew Generation With Four-Stage VCDL Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Generating precision phase skews using traditional delayed locked loops (DLLs) is difficult and expensive due to the need for a large number of delay line stages, which requires significant integrated circuit space and complex circuitry, affecting accuracy and power consumption.
Innovation Solution
A phase skew generator with an enhanced charge pump, capacitor, sample and hold circuit, and voltage-controlled delay line (VCDL) with only four delay line stages, where the delay time is adjusted by controlling the current and operation regions of the charge pump, allowing for precise phase skew generation with reduced power consumption and IC space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large number of delay line stages are used in the VCDL to generate precision phase skew, then the phase skew accuracy is improved, but the IC area and device complexity increase significantly
Solution Approach 1:
The patent changes the operating parameters of the VCDL by using an enhanced charge pump to dynamically adjust the delay time of each stage. By controlling the charge pump current and duty cycle, the system achieves precise phase skew generation with only four delay stages instead of requiring many stages, thus reducing IC area while maintaining accuracy
Solution Approach 2:
The patent implements a feedback mechanism where the phase detector continuously monitors the phase difference between input and output clocks and adjusts the charge pump control signal accordingly. This closed-loop feedback enables high precision phase skew generation with fewer delay stages by dynamically compensating for any phase errors
2Measurement precision
If a large number of delay line stages are used in the VCDL to generate precision phase skew, then the phase skew accuracy is improved, but the power consumption increases
Solution Approach 1:
The enhanced charge pump dynamically adjusts the duty cycle and current based on the required phase skew amount. By optimizing these parameters, the system achieves precise phase control with minimal power consumption, avoiding the need to operate many delay stages at full power
Solution Approach 2:
The system uses only four delay stages instead of the many stages that would be required in traditional designs. This partial action approach reduces power consumption significantly while the enhanced charge pump provides the necessary precision through parameter optimization rather than through sheer number of stages
3Adaptability or versatility
If the number of delay stages is made adjustable to change the ratio M, then the adaptability is improved, but the device complexity increases due to required multiplexer and additional circuitry
Solution Approach 1:
The patent achieves ratio adjustability by changing the control parameters of the enhanced charge pump rather than reconfiguring the delay line structure. The charge pump can be controlled to provide different effective delay ratios through current and duty cycle adjustment, eliminating the need for multiplexers and complex switching circuitry
Solution Approach 2:
The enhanced charge pump serves multiple functions: it provides the delay control signal, enables ratio adjustment, and maintains phase precision all through a single circuit block. This multi-functionality replaces what would otherwise require separate adjustable delay stages, multiplexers, and control logic
4Adaptability or versatility
If a multiplexer is added to select the M stage output of a configurable VCDL, then the adaptability is improved, but the measurement precision deteriorates due to significant and difficult-to-characterize delay time of the multiplexer
Solution Approach 1:
The patent removes the multiplexer from the signal path entirely. Instead of using a multiplexer to select different delay stage outputs, the system uses the enhanced charge pump to directly control the delay amount, eliminating the source of uncharacterized delay and precision errors
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves significant reductions in the number of delay line stages, power consumption, and IC space while maintaining precision phase skew accuracy, improving electromagnetic performance and reducing the complexity of circuitry.
Implementation Method 1
a capacitor (106), coupled to the charge pump, and configured to be charged and discharged by the charge pump, wherein the capacitor provides a voltage level reflecting the phase error
Data Source
AI summary
A method and apparatus of generating precision phase skews is disclosed. In some embodiments, a phase skew generator includes: a charge pump having a first mode of operation and a second mode of operation, wherein the first mode of operation provides a first current path during a first time period, and the second mode of operation provides a second current path during a second time period following the first time period; a sample and hold circuit, coupled to a capacitor, and configured to sample a voltage level of the capacitor at predetermined times and provide an output voltage during a third time period following the second time period; and a voltage controlled delay line, coupled to the sample and hold circuit, and having M delay line stages each configured to output a signal having a phase skew offset with respect to preceding or succeeding signal.