Bias Voltage Generation Circuit for Clock Phase Alignment

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Solution Overview

Problem

In communication systems without a clock signal, frequency drift and oscillator variations can lead to improper clocking of data signals, necessitating data clock recovery systems with phase generators to align sampling clocks accurately.

Innovation Solution

A bias voltage generation circuit with voltage-to-current and current-to-voltage translation circuits, along with a current mirror, is used to generate bias voltages that adjust the phase interpolator's bias current and loading bandwidth, allowing automatic frequency tracking and improved clock phase alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequency drift and oscillator variations occur in communication systems without clock signals, then data signal frequency stability deteriorates, but data clock recovery systems with phase generators are required to maintain proper sampling alignment

Engineering Contradiction:
Improvedata sampling alignment accuracyVSAvoidphase generator circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs parameter changes by dynamically adjusting the bias current and loading bandwidth of the phase interpolator based on the frequency of the data stream. The bias voltage generation circuit modifies operational parameters (bias current, loading bandwidth) to track frequency variations, thereby maintaining accurate sampling alignment without requiring complex external clock recovery mechanisms

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback through automatic frequency tracking mechanisms where the phase generator continuously monitors and adjusts its operation based on the actual frequency of the incoming data stream. The bias voltage generation circuit provides feedback control by adjusting bias currents to maintain optimal phase alignment, creating a self-correcting system that adapts to frequency drift

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the phase interpolator operates with fixed bias current and loading bandwidth, then circuit design is simplified, but frequency tracking capability and adaptability to varying data stream frequencies deteriorate

Engineering Contradiction:
Improvefrequency tracking capabilityVSAvoidbias voltage generation circuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by transitioning from fixed bias current and loading bandwidth to dynamically adjustable parameters. The bias voltage generation circuit continuously adapts the bias current and loading bandwidth of the phase interpolator to match the frequency characteristics of the data stream, enabling real-time frequency tracking while maintaining circuit functionality

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements self-service through automatic frequency tracking where the phase generator system monitors its own performance and self-adjusts its bias conditions. The circuit automatically detects frequency variations in the data stream and adjusts its own operating parameters without external intervention, making the system self-adapting to frequency changes

Inventive Principle:
Principle #25Self-service

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

This solution enhances the accuracy and adaptability of data clock recovery systems by maintaining optimal bias current and loading bandwidth, even with varying data stream frequencies, thereby ensuring proper sampling of data signals.

Implementation Method 1

a voltage-to-current translation circuit configured to generate a first current that is positively related to a first voltage

Methodology Applied
Scientific EffectVoltage-to-current translation: Ohm's Law

Implementation Method 2

A current mirror circuit is configured to generate a first bias voltage that is negatively related to the first current. The current mirror circuit also generates a second current that is positively related to the first current

Methodology Applied
Scientific EffectCurrent mirror effect: Electrical Resistance

Implementation Method 3

a current-to-voltage translation circuit configured to generate a second bias voltage that is positively related to a second current

Methodology Applied
Scientific EffectCurrent-to-voltage translation: Ohm's Law

Data Source

PatentUS7816975B2Circuit and method for bias voltage generation
Publication Date: 2010.10.19 VALTRUS INNOVATIONS LTD
  • US7816975B2 patent drawing
  • US7816975B2 patent drawing
  • US7816975B2 patent drawing

AI summary

A bias voltage generation circuit is provided which includes a voltage-to-current translation circuit configured to generate a first current that is positively related to a first voltage. A current mirror circuit is configured to generate a first bias voltage that is negatively related to the first current. The current mirror circuit also generates a second current that is positively related to the first current. Also employed is a current-to-voltage translation circuit configured to generate a second bias voltage that is positively related to the second current.