XR21B1411 ENHANCED 1-CH FULL-SPEED USB UART JULY 2016 REV. 1.2.0 GENERAL DESCRIPTION FEATURES The XR21B1411 (B1411) is an enhanced Universal Asynchronous Receiver and Transmitter (UART) with 15kV HBM ESD on USBD+/USBD- a USB interface. The USB interface is fully compliant USB 2.0 Compliant, Full-Speed (12 Mbps) 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 supports USB suspend, resume and remote wakeup wakeup operations operations. Unique preprogrammed USB serial number The B1411 operates from an internal clock that is Enhanced UART Features programmable to 6, 12, 24 or 48 MHz. Therefore, no Data rates up to 12 Mbps external crystal / oscillator is required as in previous Fractional Baud Rate Generator generation UARTs. With the fractional baud rate 128 byte TX FIFO generator, any baud rate up to 12 Mbps can be 384 byte RX FIFO accurately generated using the internal clock. 7, 8 or 9 data bits The large 128-byte Tx FIFO and 384-byte Rx FIFO of 1 or 2 stop bits the B1411 help to optimize the overall data Odd, even, mark, space or no parity throughput for various applications. The automatic Automatic Hardware (RTS/CTS or DTR/DSR) transceiver direction control feature simplifies both Flow Control the hardware and software for half-duplex RS-485 Automatic Software (Xon/Xoff) Flow Control applications. If required, the multidrop (9-bit) mode Multidrop mode with automatic half-duplex transceiver control feature Auto RS-485 Half-Duplex Control further simplifies typical multidrop RS-485 Half-Duplex mode applications. Selectable GPIO or Modem I/O The Vendor ID, Product ID, bus-powered mode, self- Internal 48 MHz clock with clock divisors powered mode, remote wakeup support or maximum programmable down to 6 MHz power consumption values, as well as default baud rate settings can be programmed using the on-board Single 5V power supply OTP through the USBD+ / USBD- pins. 5V tolerant inputs The B1411 operates from a single 5V power supply 16-pin QFN package and is available in a 16-pin QFN package. Virtual COM Port WHQL/HCK Windows certified WHQL certified software drivers for Windows 2000, drivers XP, Vista, 7, 8, 8.1, 10 and CE, as well as Linux and Mac are supported for the XR21B1411. Windows 2000, XP, Vista, 7, 8, 8.1 and 10 Windows CE 4.2, 5.0, 6.0, 7.0 APPLICATIONS Linux, Mac drivers Portable Appliances External Converters (dongles) Battery-Operated Devices Cellular Data Devices Factory Automation and Process Controls Industrial applications Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com XR21B1411 ENHANCED 1-CH FULL-SPEED USB UART REV. 1.2.0 FIGURE 1. XR21B1411 BLOCK DIAGRAM 1.6V-3.6V VIO REF Internal Fractional 128-byte Programmable TX BRG TX FIFO Oscillator (6MHz 48MHz) 384-byte RX RX FIFO USBD+ USB Slave Interface Internal USBD- GPIO5/RTS /RS485 Status and GPIO4/CTS Control GPIO3/DTR GPIOs/ Registers GPIO2/DSR Modem IO USB OTP GPIO1/CD Descriptors GPIO0/RI 5V VCC UART GND FIGURE 2. PIN OUT DIAGRAM 16 15 14 13 LOWPOWER 1 12 VIO REF NC 2 16-Pin 11 VBUS SENSE QFN GPIO5/RTS /RS485 3 10 RX GPIO4/CTS 4 9 TX 567 8 ORDERING INFORMATION PART NUMBER PACKAGE OPERATING TEMPERATURE RANGE DEVICE STATUS XR21B1411IL16-F 16-pin QFN -40C to +85C Active XR21B1411IL16TR-F 16-pin QFN -40C to +85C Active XR21B1411IL16MTR-F 16-pin QFN -40C to +85C Active NOTE: TR = Tape and Reel, MTR = Mini Tape and Reel, F = Green / RoHS 2 GPIO3/DTR VCC GPIO2/DSR USBD+ GPIO1/CD USBD- GPIO0/RI /RWK GND