XR21V141x Full-Speed USB UART

Exar's XR21V141x is an enhanced universal asynchronous receiver and transmitter (UART) with a USB interface. The USB interface is fully compliant to full speed USB 2.0 specification that supports 12 Mbps USB data transfer rate. The USB interface also supports USB suspend, resume, and remote wakeup operations.

The XR21V141x operates from an internal 48 MHz clock. Therefore, no external crystal/oscillator is required like previous generation UARTs. With the fractional baud rate generator, any baud rate can be generated accurately using the internal 48 MHz clock.

The large 128-byte TX FIFO and 384-byte RX FIFO of the XR21V141x help optimize the overall data throughput for various applications. The automatic transceiver direction control feature simplifies both the hardware and software for half-duplex RS-485 applications. The multi-drop (9-bit) mode with automatic half-duplex transceiver control feature further simplifies typical multi-drop RS-485 applications.

The XR21V141x operates from a single 2.97 to 3.63 V power supply and has 5 V tolerant inputs. Virtual COM port drivers for Windows 2000, XP, Vista, and CE as well as Linux and Mac are available for the XR21V141x.