CMADS Transmitter Reducing Power via Floating Terminals

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Solution Overview

Problem

In high-density semiconductor integrated circuits, existing data transmission technologies face challenges in accelerating data transmission speed while minimizing power consumption, particularly in mobile devices where parasitic capacitance limits voltage signal acceleration and results in unnecessary power usage during dummy data transfers.

Innovation Solution

The proposed solution involves a transmitter and receiver system using a pair of output terminals where one terminal is connected to a reference potential and the other is in a floating state, generating complimentary current signals only when image data is outputted, and a control signal indicates the presence or absence of image data to manage current flow, reducing power consumption and wiring requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If voltage signals are used for data transmission, then transmission speed can be accelerated, but parasitic capacitance of the transmission path causes delays and limits further acceleration

Engineering Contradiction:

Improvedata transmission speedVSAvoidparasitic capacitance effect

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent replaces voltage signal transmission with current signal transmission. By using current signals instead of voltage signals, the system eliminates the parasitic capacitance effect that limits voltage signal acceleration. Current signals are not affected by parasitic capacitance in the same way, enabling faster data transmission without the delays caused by capacitive loading.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If current flows continuously in wiring cables between transmitting and receiving units, then data transmission can be maintained, but useless power is consumed during dummy transfers when no image data are transmitted

Engineering Contradiction:

Improvedata transmission continuityVSAvoidpower consumption during dummy transfers

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent implements dynamic control of current flow in the wiring cables. A control signal is introduced that can switch the transmission state between active and inactive. When dummy transfers occur and no image data are transmitted, the control signal stops current flow in the cables, eliminating useless power consumption. When real data transmission is needed, the control signal restores current flow, maintaining transmission continuity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses periodic control signals to manage the current flow state. The control signal periodically activates or deactivates current flow based on whether actual data transmission is occurring or dummy transfers are taking place. This periodic control ensures power is only consumed when necessary for meaningful data transmission.

Inventive Principle:

Principle #19Periodic action

3Reliability

If a pair of wiring cables is used for CMADS transmission, then complimentary current signals can be transmitted, but the number of wiring cables and signal lines increases device complexity

Engineering Contradiction:

Improvesignal transmission reliabilityVSAvoidnumber of wiring cables

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the control signal transmission function with the existing data transmission wiring. Instead of adding separate control signal lines, the system uses the same pair of wiring cables that carry complimentary current signals for data transmission to also carry control signals. This merging approach maintains signal transmission reliability while avoiding the increase in device complexity that would result from adding separate control lines.

Inventive Principle:

Principle #5Merging (Combining)

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 achieves low power consumption and reduces the number of wiring cables needed for data transmission among semiconductor integrated circuits, optimizing power usage and transmission efficiency, especially in mobile devices with limited space and high design constraints.

Implementation Method 1

a pair of wiring cables is provided to transmit signals between the transmitter circuit and the receiver circuit, and in the transmitter circuit one of the wiring cables is connected with the ground electrode and the other is kept in the floating state (high-impedance state). This leads to the flow of electric current in the wiring cables extending from the power source provided in the receiver circuit to the ground electrode and no flow of current to the other wiring cables. As a result, complimentary current signals can be transmitted by a pair of wiring cables.

Methodology Applied

Scientific EffectCurrent Mode Advanced Differential Signaling (CMADS):

Implementation Method 2

the receiving unit for receiving data (I-V conversion circuits 21 and 22 in FIG. 1)

Methodology Applied

Scientific EffectI-V conversion:

Data Source

PatentUS8054303B2Transmitter and receiver capable of reducing current consumption and signal lines for data transfer

Publication Date: 2011.11.08 RENESAS ELECTRONICS CORP

AI summary

A transmitter includes a pair of output terminals which output an image data, and a transmitting unit. When the transmitting unit outputs the image data, a first output terminal of the pair is connected to a reference electric potential and a second output terminal of the pair is to a floating state, based on the image data. When the transmitting unit does not output an image data, the first and second output terminals of the pair become to a floating state.