System Overview

The CP2104 is a highly-integrated USB-to-UART Bridge Controller providing a simple solution for updating RS-232/RS-485 designs to USB using a minimum of components and PCB space. The CP2104 includes a USB 2.0 full-speed function controller, USB transceiver, oscillator, one-time programmable ROM, and asynchronous serial data bus (UART) with full modem control signals in a compact 4 x 4 mm QFN-24 package (sometimes called “MLF” or “MLP”). No other external USB components are required.

The on-chip one-time programmable ROM may be used to customize the USB Vendor ID, Product ID, Product Description String, Power Descriptor, Device Release Number, Device Serial Number, and GPIO configuration as desired for OEM applications.

Royalty-free Virtual COM Port (VCP) device drivers provided by Silicon Labs allow a CP2104-based product to appear as a COM port to PC applications. The CP2104 UART interface implements all RS-232/RS-485 signals, including control and handshaking signals, so existing system firmware does not need to be modified. The device also features up to four GPIO signals that can be user-defined for status and control information. Support for I/O interface voltages down to 1.8 V is provided via a VIO pin. In many existing RS-232 designs, all that is required to update the design from RS-232 to USB is to replace the RS-232 level-translator with the CP2104. Direct access driver support is available through the Silicon Labs USBXpress driver set. See www.siliconlabs.com for the latest application notes and product support information for the CP2104.

An evaluation kit for the CP2104 (Part Number: CP2104EK) is available. It includes a CP2104-based USB-to-UART/RS-232 evaluation board, a complete set of VCP device drivers, USB and RS-232 cables, and full documentation. Contact a Silicon Labs sales representatives or go to www.siliconlabs.com to order the CP2104 Evaluation Kit.