USB use has grown in industrial applications: for software uploads and configuration, diagnostics, maintenance, and connecting peripheral modules such as Wi-Fi® routers, display screens and human-machine interface modules. However, since USB’s primary definition is as a consumer electronics interface, it is not inherently capable of handling the large noise disturbances, ground bounce and ground potential differences common in industrial applications. Also, in applications such as uninterrupted power supplies, controllers with the USB interface are on the high-voltage or “hot” side, needing protective isolation to the USB connector. Because of these reasons, isolating the USB interface has become necessary in a broad spectrum of applications, including factory automation, motor drives, medical equipment, e-meters, data concentrators, in-flight entertainment and gaming consoles.
The applications mentioned above often need the flexibility of connecting to a PC while acting as a peripheral (device), or to peripherals such as a Wi-Fi module or USB memory drive while acting as a host. In the past, system designers provided two different ports to support this functionality: one for the host and one for the peripheral - using two different USB isolators (also called isolated USB repeaters). This solution is expensive and takes up valuable board area. Instead, a USB Type-C® connector can implement a dual-role port (DRP) – one port that supports both host and peripheral functionality. This article discusses how to implement an isolated USB 2.0 USB Type-C DRP.