Optical Chip Interconnect With Differential Output and Fewer Pins

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Solution Overview

Problem

Existing electrical interfaces in chip interconnects face issues with signal integrity, crosstalk, and increased pin count, which affect performance and thermal management, especially with increasing data rates and peripheral connections.

Innovation Solution

Implementing optical fiber coupling ports and converters to convert differential data signals, reducing the number of pins by using a two-wire coupling port for optical and electrical interfaces, and employing photodetectors and amplifiers to generate and process electrical signals for improved signal integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple copper wires and parallel bus interfaces are used to connect chipset to peripherals, then data transmission capability is improved, but pin count and device complexity increase

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidpin count

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces traditional electrical copper wire connections with optical fiber connections. The optical interface uses light transmission through optical fibers instead of electrical signals through copper traces, fundamentally substituting the transmission medium. This reduces the number of pins required while maintaining high data transmission capability, as optical fibers can carry more data with fewer physical connections.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a unified optical interface architecture that can handle multiple types of data transmissions (camera data, display data, sensor data) through a single optical fiber connection. The optical coupling port serves multiple functions by transmitting different data types sequentially or in parallel through the same physical interface, eliminating the need for separate parallel bus connectors for each peripheral.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If multiple parallel bus connectors are used for cameras and displays, then data transmission capability is improved, but thermal issues worsen due to increased switching activity

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidthermal issues

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent replaces electrical signal transmission through copper traces with optical signal transmission through optical fibers. This substitution eliminates the need for high-frequency electrical switches and buffers that generate heat in traditional parallel bus interfaces. The optical interface transmits data as light pulses, requiring minimal active switching components on the chipset, thereby significantly reducing thermal generation while maintaining high data transmission rates.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If copper wire interfaces are used for high data rate transmission, then connectivity is improved, but signal integrity deteriorates due to crosstalk and interference

Engineering Contradiction:

Improvedata transmission rateVSAvoidsignal integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent substitutes electrical signal transmission through copper wires with optical signal transmission through optical fibers. Optical signals are immune to electromagnetic interference and crosstalk that plague copper-based interfaces at high data rates. The light-based transmission through isolated optical fibers eliminates capacitive coupling and inductive interference between adjacent signal lines, ensuring superior signal integrity while supporting higher transmission rates.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach enhances signal integrity and reduces the number of pins, minimizing thermal issues and maintaining high data rates across various peripherals, while supporting multiple optical fibers and differential data signals.

Implementation Method 1

a photodetector coupled to the optical fiber coupling port configured to generate an electrical signal in response to an optical signal received at the optical fiber coupling port

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS20250278378A1Chip interconnect with optical and differential signal interfaces

Publication Date: 2025.09.04 QUALCOMM INC

AI summary

Aspects relate to a chip interconnect with optical and differential signal interfaces. An apparatus includes an optical fiber coupling port, a photodetector coupled to the optical fiber coupling port configured to generate an electrical signal in response to an optical signal received at the optical fiber coupling port, a converter coupled to receive the electrical signal and configured to generate a differential data signal based on the electrical signal, and a two-wire coupling port comprising output pins of the chip interconnect, the two-wire coupling port configured to couple the differential data signal to the output pins.