The WCH CH339W is a compact USB-to-serial interface chip that enables reliable UART communication between USB hosts and serial devices. Measuring approximately 6 × 6 mm in a QFN package, its small footprint makes it ideal for space-constrained applications like embedded systems, USB adapters, industrial controllers, and IoT devices. The CH339W supports standard serial baud rates and includes on-chip USB 2.0 full-speed functionality, allowing straightforward integration without external crystals. It is widely used for USB-to-RS232/TTL converters, firmware programming tools, and serial debugging interfaces. With official WCH drivers available for Windows 11, Windows 10, and Windows Server platforms, it offers broad compatibility and dependable performance.