Configurable Glitch Filter Circuit for Noise Spike Isolation

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Solution Overview

Problem

Conventional synchronous serial communication systems, such as I2C, are susceptible to noise spikes (glitches) that cause data corruption and duty cycle distortion due to inconsistent RC filter circuitries and Schmitt triggers, which are not effective in filtering all noise spikes less than 50 ns and are prone to PVT variations.

Innovation Solution

A glitch filter circuitry with a configurable RC filter that includes a control path and data path, utilizing a tunable resistor and capacitor configuration to dynamically adjust the RC constant, isolating the RC filter from the data path to prevent duty cycle distortion and effectively filter glitches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional RC filter circuitry is used to filter noise spikes, then glitch filtering is provided, but duty cycle distortion occurs and filtering effectiveness is inconsistent due to PVT variations

Engineering Contradiction:

Improveglitch filtering effectivenessVSAvoidduty cycle accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The circuit is divided into two independent paths: a control path that processes the input signal through the RC filter to generate control signals, and a data path that processes the original input signal. This segmentation allows the RC filter to be isolated from the data path, preventing duty cycle distortion while maintaining glitch filtering effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A control signal is introduced as an intermediary between the RC filter and the data path. The control signal carries the filtered information without directly connecting the RC filter to the data path, thereby preventing duty cycle distortion while maintaining the ability to detect and respond to glitches.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If Schmitt triggers are used for noise filtering, then some noise spikes are filtered, but glitches less than 50 ns are not effectively filtered and false data detection occurs

Engineering Contradiction:

Improvenoise spike filteringVSAvoiddata detection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The RC time constant is made configurable through selectable resistance and capacitance values, allowing the filter to be adapted to different noise characteristics and signal frequencies. This enables effective filtering of various glitch durations including those less than 50 ns while maintaining accurate data detection.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If fixed RC filter values are used, then circuit simplicity is maintained, but adaptability to different noise conditions and PVT variations is poor

Engineering Contradiction:

Improvecircuit simplicityVSAvoidnoise filtering adaptability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The RC filter values are made dynamically selectable through multiple resistance and capacitance options that can be configured based on operating conditions. This allows the filter to adapt to different noise conditions and PVT variations while maintaining a relatively simple circuit structure using standard electronic components.

Inventive Principle:

Principle #15Dynamics

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 glitch filter circuitry ensures accurate signal processing by isolating the RC filter, minimizing duty cycle distortion and false data detection, while adaptively filtering noise spikes, thereby enhancing signal integrity and reliability.

Implementation Method 1

a configurable resistor capacitor (RC) filter circuitry configured to deliver a configurable RC filter circuitry output signal based on one or more selection signals

Methodology Applied

Scientific EffectRC filtering: Filter (electronic)

Data Source

PatentUS20260031793A1Glitch filter circuitry for device-to-device communication system interface

Publication Date: 2026.01.29 ADVANCED MICRO DEVICES INC

AI summary

A computing system includes a communication system comprising a glitch filter circuitry disposed in an integrated circuit (IC) device configured to receive an input signal and provide a glitch filter output signal based on the input signal. The glitch filter circuitry includes a control path circuitry configured to receive the input signal and generate a control signal based on detecting a glitch within the input signal, the control path circuitry including a configurable resistor capacitor (RC) filter circuitry configured to deliver a configurable RC filter circuitry output signal based on one or more selection signals. The control signal is based on the configurable RC filter circuitry output signal, and a data path circuitry configured to receive the control signal and mitigate glitches within the input signal based on the control signal.