USB Isolator Circuit for Controlled Enumeration and Status Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing USB isolators lack the capability for controlled enumeration and effective communication of status between upstream and downstream circuit systems, limiting their functionality in galvanically isolated environments.
Innovation Solution
A USB isolator system that supports controlled enumeration by using a multi-mode voltage regulator, refresh timers, and watchdog mechanisms to manage communication errors, enabling robust control and power-efficient operation across isolated circuit systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a USB isolator provides basic data transmission across an isolation barrier, then galvanic isolation is achieved, but controlled enumeration and status communication capabilities are lost
Solution Approach 1:
The USB isolator is divided into separate upstream and downstream circuit systems that are galvanically isolated from each other. Each side operates independently with its own voltage domain, allowing reliable isolation while maintaining full USB functionality including enumeration and status communication through the isolation barrier.
Solution Approach 2:
The isolator acts as an intermediary device between upstream and downstream USB circuit systems, translating and transmitting signals across the galvanic isolation barrier. It mediates enumeration requests, status communications, and data transfer while maintaining voltage domain separation, enabling controlled enumeration despite the isolation.
2Reliability
If USB data transmission occurs across galvanically isolated systems operating in different voltage domains, then isolation is maintained, but communication of status between systems becomes inadequate
Solution Approach 1:
The USB isolator is designed to perform multiple functions simultaneously: it maintains galvanic isolation, transmits data bidirectionally, communicates status between upstream and downstream systems, and supports controlled enumeration. This multi-functionality ensures that status information is not lost while maintaining the isolation barrier.
Solution Approach 2:
The isolator implements feedback mechanisms that allow downstream circuit systems to communicate status information back to upstream systems across the isolation barrier. Status signals are transmitted and recognized by the upstream side, enabling bidirectional status communication while maintaining galvanic isolation through controlled signal translation.
Data Source
AI summary
A USB-based isolator system conveys USB signals between a pair of galvanically isolated circuit systems and supports controlled enumeration by a downstream device on upstream USB signal lines. The isolator system provides a multi-mode voltage regulator to support multiple voltage supply configurations. The isolator system further provides control systems for each of the isolated circuit systems and provides robust control in a variety of start up conditions. Additionally, the isolator system includes refresh timers and watchdog mechanisms to support persistent operation but manage possible communication errors that can arise between the isolated circuit systems.