USB to Serial Port Chip CH9101
CH9101N is a high-speed USB-to-UART bridge IC developed by WCH (Qinheng Electronics). It converts a USB 2.0 Full-Speed interface into a standard asynchronous UART serial interface, enabling seamless communication between a computer and microcontrollers, embedded systems, industrial equipment, and other UART-based devices. The device features an integrated clock oscillator and power-on reset circuitry, minimizing external components and simplifying PCB design. Housed in a compact SOP-8 package, the CH9101N supports UART logic voltages from 1.8 V to 5 V, making it suitable for a wide range of low-power and mixed-voltage applications. It is commonly used for USB debugging, firmware downloading, serial communication, and IoT development.
Key Features
USB 2.0 Full-Speed compliant device interface
USB-to-UART bridge with baud rates up to 3 Mbps
Supports 1.8 V, 2.5 V, 3.3 V, and 5 V UART I/O levels
Integrated clock oscillator (no external crystal required)
Built-in power-on reset circuitry
Full-duplex UART communication
Supports hardware flow control (RTS/CTS)
Compatible with standard virtual COM port (VCP) drivers
Compact SOP-8 package with minimal external components
Suitable for MCU programming, debugging, and serial communication applications