Shared RC Filtering for Stable I2C Clock Pulse Rejection

Solution Overview

Problem

Conventional RC filter circuits for I2C bus signals are bulky, consume significant current, and exhibit relative variations due to fabrication tolerances, leading to inefficiencies in signal filtering and potential misinterpretation of communication conditions.

Innovation Solution

An electronic device with shared resistive circuits and dedicated capacitive circuits in elementary filtering modules, which cooperate to filter signals independently, reducing space and current consumption while homogenizing filter behavior and minimizing variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional RC filter circuits are used for I2C bus signals, then signal filtering is achieved, but the circuits are bulky and consume significant current

Engineering Contradiction:

Improvesignal filtering performanceVSAvoidcircuit area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Multiple filtering modules share a common resistive circuit instead of each module having its own dedicated resistor. This merging of the resistive component reduces the total area occupied by the filtering circuits while maintaining the necessary signal filtering performance for I2C bus communications.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The common resistive circuit serves multiple filtering modules simultaneously, making it a universal component that performs the same filtering function for several different signal paths. This multi-functionality reduces redundancy and minimizes the overall circuit area.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If conventional RC filter circuits are used for I2C bus signals, then signal filtering is achieved, but current consumption is significant

Engineering Contradiction:

Improvesignal filtering performanceVSAvoidcurrent consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Multiple filtering modules share a common resistive circuit instead of each module having its own dedicated resistor. This merging of the resistive component reduces the total area occupied by the filtering circuits while maintaining the necessary signal filtering performance for I2C bus communications.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The common resistive circuit serves multiple filtering modules simultaneously, making it a universal component that performs the same filtering function for several different signal paths. This multi-functionality reduces redundancy and minimizes the overall circuit area.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If conventional RC filter circuits are used for I2C bus signals, then filtering is provided, but fabrication tolerances cause relative variations in filter behavior

Engineering Contradiction:

Improvefiltering functionVSAvoidfilter behavior consistency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

Each filtering module maintains its own dedicated capacitive circuit while sharing the resistive circuit. This allows local adjustment and optimization of the capacitive components to compensate for variations in the shared resistive circuit, ensuring consistent filter behavior across all modules despite fabrication tolerances.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The filtering characteristics are adjusted by modifying the capacitive values in each module to compensate for variations in the shared resistive circuit. By changing the capacitive parameters locally, consistent filter behavior can be achieved across all modules despite variations in the common resistive component due to fabrication tolerances.

Inventive Principle:

Principle #35Parameter changes

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 a compact design, reduces energy consumption, and stabilizes filter performance by sharing resistive circuits among multiple filtering modules, ensuring consistent behavior and accurate signal processing.

Implementation Method 1

each elementary filtering module comprising an elementary input intended to receive an incident elementary signal extracted from the incoming signal, an elementary output and a dedicated capacitive circuit

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

a resistive circuit common to all the elementary filtering modules and configured for cooperating with the capacitive circuit of each elementary filtering module in such a manner that each elementary filtering module can filter pulses

Methodology Applied

Scientific EffectResistive-capacitive filtering: Electrical Resistance

Data Source

PatentUS10558609B2Apparatus for inter-integrated circuit (I2C) clock transmission channel wherein each filtering modules cooperates with the resistive circuit

Publication Date: 2020.02.11 STMICROELECTRONICS (ROUSSET) SAS

AI summary

In an embodiment, an electronic device for filtering an incoming digital signal includes several elementary filtering modules that include an elementary input configured to receive an incident elementary signal extracted from an incoming signal, an elementary output, and a dedicated capacitive circuit. The device further includes a resistive circuit common to all the elementary filtering modules and configured for cooperating with the capacitive circuit of each elementary filtering module in such a manner as to filter, on the respective elementary output, pulses of the incident elementary signal having a first voltage level and a duration less than a time constant and to deliver a filtered elementary signal on the elementary output.