System Overview

The CP2105 is a highly-integrated USB-to-Dual-UART Bridge Controller providing a simple solution for updating RS-232 designs to USB using a minimum of componentsand PCB space. The CP2105 includes a USB 2.0 full speed function controller, USB transceiver, oscillator, one-time programmable ROM, and two asynchronous serial data buses (UART) with full modem control signals in a compact 4 x 4 mm QFN-24 package (sometimes called “MLF” or “MLP”).

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

Royalty-free Virtual COM Port(VCP) device drivers provided by SiliconLabs allow a CP2105-based product to appear as two COM ports in PC applications. The CP2105 UART interfaces implement all RS-232 signals including control and handshaking, so existing system firmware does not need to be modified. The device also features a total of five 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 VIOpin. Direct access driver support is also available through the Silicon Labs USBXpress driver set.See www.silabs.com for the latest application notes and product support information for the CP2105. An evaluation kit for the CP2105 (Part Number: CP2105EK) is available. It includes a CP2105-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.silabs.com to order the CP2105 Evaluation Kit.