Randomized Enable Signal Generator for EMC Compliance
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Solution Overview
Problem
Integrated circuits face challenges in meeting electromagnetic compatibility (EMC) specifications due to difficulties in predicting performance, lack of device models for the appropriate frequency range, and understanding the consequences of design decisions on EMC results, particularly related to power consumption and frequency content generated through supply pins.
Innovation Solution
An improved enable signal generator that randomly selects time slots to activate digital functions, spreading the current spectrum over a large bandwidth and suppressing undesired tones, thereby enhancing EMC/EMI performance by using a selection circuitry to generate a randomized enable signal based on a clock signal with N type-1 features in a given time period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a deterministic enable signal is used to control digital functions, then the system operation is simple and predictable, but the electromagnetic emissions concentrate at specific frequencies making it difficult to meet EMC specifications
Solution Approach 1:
The patent applies dynamics by transitioning from a deterministic, static enable signal pattern to a randomized, dynamic pattern. The enable signal generator randomly selects time slots to activate digital functions, causing the enable signal to vary dynamically over time. This randomization spreads the spectral content of electromagnetic emissions across a wider frequency range, reducing peak emissions at any single frequency and improving EMC compliance while maintaining operational simplicity through automated random selection.
2Productivity
If digital functions are activated continuously, then the system maintains high operational efficiency, but the current spectrum concentrates at specific frequencies creating harmful electromagnetic emissions
Solution Approach 1:
The patent implements periodic action through the structured random selection process. The enable signal generator operates in periodic cycles, randomly selecting time slots within each period to activate digital functions. This periodic randomization maintains operational efficiency by ensuring functions are activated at regular intervals while distributing the activation pattern randomly across different time slots, thereby spreading the current spectrum over a wider bandwidth and reducing concentration at specific frequencies.
3Object-generated harmful factors
If a randomized enable signal is generated by selecting time slots from N total time slots, then electromagnetic emissions are spread across wider bandwidth, but the complexity of the enable signal generator increases
Solution Approach 1:
The patent applies self-service through the autonomous operation of the enable signal generator. The generator automatically randomizes the selection of time slots without requiring external intervention or complex control logic. The random number generator and selection circuitry operate independently to produce the enable signal, eliminating the need for manual configuration or complex external control systems. This self-service approach achieves broad spectral distribution of emissions while keeping the generator's internal complexity manageable through automated, independent operation.
Data Source
AI summary
A system comprising: a clock configured to generate a clock signal, the clock signal being arranged to have N type-1 features in a given time period, each of the N type-1 features of the clock signal being generated in a different one of a plurality of time slots of the given time period; a signal generator configured to generate a randomized signal based on the clock signal, the randomized signal being generated by selecting M time slots from the plurality of time slots and transitioning the randomized signal from a first value to a second value in each of the selected M time slots, wherein M and N are positive integers and M<N.