USB Type-C DRP Controller Power Role Switching

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Solution Overview

Problem

In the USB Type-C standard, when devices configured as Dual Role Power (DRP) are connected, the Power Role (SRC/SNK) is not uniquely determined, leading to ambiguity in power supply and reception roles, especially when Try.SRC or Try.SNK devices are involved.

Innovation Solution

A controller is implemented to dynamically switch the Port Power Role from Try.SRC or Try.SNK to SRC or SNK only based on specific switching conditions, ensuring that the Power Role is uniquely determined by executing a control method that assesses the opposing device's Port Power Role and adjusts accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If DRP devices are used to support both power supply and reception at one port, then device versatility and cost reduction are improved, but Power Role determination becomes ambiguous when Try.SRC or Try.SNK devices are connected

Engineering Contradiction:

ImprovePower Role adaptabilityVSAvoidPower Role determination reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The controller dynamically switches the Port Power Role from Try.SRC or Try.SNK to SRC or SNK only based on detected connection states and communication results. This dynamic adjustment resolves the ambiguity by adapting the power role configuration in real-time according to the actual connection scenario, ensuring reliable power role determination while maintaining the versatility benefits of DRP devices

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller executes a sequence with the opposing device to detect its Port Power Role, then uses this feedback information to determine whether to switch its own Port Power Role. This feedback mechanism ensures that power role assignment is based on actual connection conditions rather than fixed configurations, resolving the ambiguity inherent in Try.SRC/Try.SNK configurations

Inventive Principle:

Principle #23Feedback

2Device complexity

If Try.SRC or Try.SNK Port Power Role is used to reduce device complexity, then the number of ports is reduced, but the Power Role becomes non-unique leading to control ambiguity

Engineering Contradiction:

ImprovePort configuration complexityVSAvoidPower Role information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The controller performs preliminary detection of the opposing device's Port Power Role through sequence execution before finalizing its own power role configuration. This preliminary action prevents power role ambiguity by gathering necessary information in advance, ensuring that the controller switches to SRC or SNK only when appropriate rather than relying on ambiguous Try.SRC/Try.SNK states

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11281271B2Controller, control method, and control program

Publication Date: 2022.03.22 RENESAS ELECTRONICS CORP

AI summary

The present invention solves a new problem that may occur when Try.SRC or Try.SNK is adopted. A controller is used to implement a DRP-compliant device that can be both power supply side and power reception side according to the USB Type-C standard. The controller is configured to be able to execute a first process of determining whether or not the Port Power Role of the opposing device is Try.SRC when the Power Role of the own device is determined to be Sink meaning the power receiver according to the sequence with the opposing device, which is the connected device, and a second process of switching the Port Power Role of the own device to SRC only and continuing the sequence with the opposing device if the Port Power Role of the opposing device is Try.SRC.