Integrated Clock Generator with PVT-Stable Low-Jitter Timing

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Solution Overview

Problem

Existing clock generators, such as crystal oscillators, cannot be integrated with microprocessors as a single IC, leading to separate off-chip clock generators, and other integrated clock generators lack accuracy due to PVT variations, frequency drift, and noise sensitivity.

Innovation Solution

A monolithically integrated clock generator system using an LC-tank oscillator, transconductance amplifier, frequency controller, and temperature compensator, which generates a low-jitter, free-running clock signal without requiring a separate reference oscillator, and can switch between power conservation and power resumption modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If crystal oscillators are used for accurate clock generation, then clock accuracy is improved, but integration with microprocessors is worsened (separate off-chip components required)

Engineering Contradiction:

Improveclock accuracyVSAvoidintegration

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the clock generator functionality with the microprocessor onto a single integrated circuit chip. The clock generator includes an oscillator, frequency divider, and control logic that are monolithically integrated with the microprocessor core, eliminating the need for separate off-chip crystal oscillators while maintaining clock accuracy through integrated temperature compensation and frequency control mechanisms.

Inventive Principle:

Principle #5Merging (Combining)

2Device complexity

If integrated clock generators are used to improve integration, then device complexity is reduced, but clock accuracy deteriorates due to PVT variations and noise

Engineering Contradiction:

ImproveintegrationVSAvoidclock accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms within the integrated clock generator, including phase-locked loops (PLL) that continuously monitor and adjust the clock frequency to compensate for process, voltage, and temperature (PVT) variations. Temperature sensors provide feedback to adjust oscillation frequency, and frequency dividers with feedback control maintain stable clock signals despite integrated circuit noise and parameter drift.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent employs parameter changes to maintain clock accuracy across varying conditions. Temperature compensation circuits dynamically adjust oscillation parameters based on detected temperature changes, voltage regulation circuits adjust operating points based on supply voltage variations, and frequency control mechanisms modify divider ratios to maintain precise clock frequencies despite PVT variations inherent in integrated circuit operation.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If power conservation mode is implemented, then energy consumption is reduced, but clock signal continuity is worsened

Engineering Contradiction:

Improvepower consumptionVSAvoidclock signal continuity

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of stationary object

Solution Approach 1:

The patent implements periodic action through burst-mode clock generation in power conservation state. Instead of continuously generating clock signals, the integrated clock generator produces periodic clock bursts or pulsed clock signals at reduced frequency intervals, allowing the microprocessor to enter low-power sleep states between bursts while maintaining the ability to quickly resume full operation when needed, thus reducing average power consumption while preserving essential clock functionality.

Inventive Principle:

Principle #19Periodic action

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 system provides highly accurate, low-jitter clock signals that are stable over PVT and aging variations, suitable for precise applications, and can substitute for quartz crystal oscillators, with fast rise and fall times and multiple operating modes, including power conservation.

Implementation Method 1

an LC-tank oscillator

Methodology Applied

Scientific EffectLC resonance: Resonance

Implementation Method 2

transconductance amplifier

Methodology Applied

Scientific EffectTransconductance:

Implementation Method 3

temperature compensator

Methodology Applied

Scientific EffectTemperature compensation:

Data Source

PatentUS8095813B2Integrated circuit systems having processor-controlled clock signal generators therein that support efficient power management

Publication Date: 2012.01.10 RENESAS ELECTRONICS AMERICA INC

AI summary

Exemplary embodiments of the invention provide a clock generation apparatus, system, and method, which include power management. The apparatus is couplable to second circuitry which has a clock input terminal and an inverted clock output terminal. An exemplary apparatus comprises a clock generator, a sensor, and a processor. The clock generator provides a clock signal on a first terminal which is couplable to the clock input terminal of the second circuitry. The sensor is coupled to a second terminal which is couplable to the inverted clock output terminal, and detects a power conservation mode and a power resumption mode of the second circuitry. The processor is adapted to reduce power to the clock generator and to provide a first predetermined voltage or a second predetermined voltage to the first and second terminals in response to the detection of the power conservation mode, and to increase power to the clock generator in response to the detection of the power resumption mode.