XR21B1421IL24-F

XR21B1421 Enhanced 1-Ch Full-Speed USB HID to UART Bridge General Description FEATURES The XR21B1421 is an enhanced Universal Asynchronous Receiver and Transmitter (UART) bridge to HID class USB interface. The USB interface is fully compliant to the USB 2.0 (Full-Speed) specification with 12 Mbps USB data transfer rate. The USB interface also supports USB suspend, resume and remote wakeup operations. The USB Vendor ID, Product ID, power mode, remote wakeup support, maximum power, and numerous other settings may be programmed in the on-chip OTP memory via the USB interface using either HID reports or MaxLinear-supplied OTP programming tools. The XR21B1421 includes an internal oscillator and does not require an external crystal/oscillator. Any UART baud rate up to 12 Mbps may be generated with this internal clock and the fractional baud rate generator. The UART pins for each port may also be configured as GPIO; direction, state, output driver type and input pull-up or pull-down resistors are programmed either through on chip OTP, or on the fly via memory mapped registers. Large 512-byte TX and RX FIFOs prevent buffer overflow errors and optimize data throughput. Automatic half-duplex direction control and optional multi drop (9-bit) mode simplify both hardware and software in half-duplex RS-485 applications. The XR21B1421 uses the native OS HID driver using HID reports. The HID reports perform a variety of functions, including device configuration, transmitting and receiving UART data, and programming of the on-chip OTP. MaxLinear provides a .dll as an easy to use programming interface to the HID reports. • ±15kV ESD on USBD+/USBD• USB 2.0 Compliant, Full-Speed (12Mbps) • Unique pre-programmed USB serial number • Internally generated 48MHz core clock • Enhanced UART features • Baud rates up to 12 Mbps • Fractional Baud Rate Generator • 512-byte TX and 512-byte RX FIFOs • Auto Hardware / Software Flow Control • Multidrop and Half-Duplex Modes • Auto RS-485 Half-Duplex Control • Selectable GPIO or Modem I/O • Up to 10 GPIOs • 5V tolerant GPIO inputs • Suspend state GPIO configuration • Configurable clock output • 24-pin or 28-pin QFN package • Industrial -40°C to +85°C Temperature Range APPLICATIONS • Portable Medical Diagnostics • Blood Glucose Meters • Health and Fitness Wellness Monitors • Uninterruptible Power Supplies • Energy Management Consoles Ordering Information – page 54 The XR21B1421 operates from a single 5V or 3.3V power supply and is available in a 24 or 28 pin QFN package. When powered with 5V input, the XR21B1421 supplies a regulated 3.3V output. The 24 pin package has a separate VIO supply voltage input for the Modem / GPIO pins. The 28 pin package has VIO internally tied to 3.3V. Block Diagram Internal Oscillator (48MHz) USB Fractional BRG USB Slave Interface USB Descriptors Internal Status and Control Registers 512-byte TX FIFO TX 512-byte RX FIFO RX GPIOs/ Modem IO OTP UART LDO • www.maxlinear.com • 263DSR00 3V3 XR21B1421 Absolute Maximum Ratings Operating Conditions Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Maximum Rating may affect device reliability and lifetime. Operating Temperature Range.....................-40°C to +85°C Supply Voltage (VCC_REG)......................................+5.75V Supply Voltage (VCC, VIO)............................................+4V Input Voltage (VBUS_SENSE).......................-0.3 to +5.75V Input Voltage (All other pins)............................-0.3 to +5.6V Junction Temperature.................................................125°C Electrical Characteristics Unless otherwise noted: TA = -40°C to +85°C, VCC_REG = 4.4V to 5.25V or 3.0V to 3.6V, VIO = 1.8V to 3.6V Symbol Parameter Conditions Min Typ Max Units 13 19 mA 0.85 1.25 mA 3.3 3.6 V Power ICC Power Supply Current ISUSP Suspend Mode Current VOUT Regulated Output Voltage (VCC pin) VCC_REG = +4.4V to +5.25V (Does not include current that VOUT sources to external devices or to VIO) VCC_REG = +4.4V to +5.25V. Maximum output current = 200 mA including the supply current of the XR21B1421. 3 UART, USB_STAT and GPIO Pins VIL Input Low Voltage -0.3 0.25* VIO V VIH Input High Voltage 0.70* VIO 5.5 V VOL Output Low Voltage IOL = 1mA, VIO = +1.6V 0.3 V IOL = 4mA, VIO = +3.6V 0.5 V VOH Output High Voltage IOH = -400uA, VIO = +1.6V 1.3 VIO V IOH = -1.5mA, VIO = +3.6V 2.8 VIO V IIL Input Low Leakage Current VIO = +3V to +3.6V, VCC_REG = +4.4V to +5.25V, VINPUT = 0V ±10 µA IIH Input High Leakage Current VIO = +3V to +3.6V, VCC_REG = +4.4V to +5.25V, VINPUT = +3.3V ±10 µA VIO = +3V to +3.6V, VCC_REG = +4.4V to +5.25V, VINPUT = +5.5V ±120 µA 5 pF CIN 263DSR00 Input Pin Capacitance 2 Rev. 1E XR21B1421 Symbol Parameter Conditions Min Typ Max Units USB I/O Pins VIL Input Low Voltage -0.3 0.8 V VIH Input High Voltage 2.0 5.5 V VOL Output Low Voltage External 15kΩ to GND on USBD+ and USBD- pins 0 0.3 V VOH Output High Voltage External 15kΩ to GND on USBD+ and USBD- pins 2.8 3.6 V VDrvZ Driver Output Impedance 28 44 Ω 263DSR00 3 Rev. 1E XR21B1421 14 GPIO7/RI#/RWK# E_PAD 8 9 10 11 12 VBUS_SENSE RESET# NC USB_STAT1 GPIO9/DSR# 13 7 6 VCC_REG VCC GPIO8/DTR# 24-Pin Top View 263DSR00 GPIO4/TXT GPIO5/RXT TX RX GPIO1/RTS#/RS485 GPIO2/CTS# NC 27 26 25 24 23 22 NC USBD- 5 17 GPIO7/RI#/RWK# VCC 6 16 GPIO8/DTR# VCC_REG 7 15 TEST# E_PAD NC 5 18 14 VIO 4 USBD+ 13 GPIO6/CD# NC 15 12 4 GPIO6/CD# 3 USB_STAT1 USBD- 19 GND 11 NC NC 2 USB_STAT2 16 20 GPIO0/CLK MaxLinear XR21B1421 10 3 28 19 GPIO4/TXT USB_STAT2 NC 1 GPIO9/DSR# USBD+ 20 RX 17 MaxLinear XR21B1421 21 GPIO3/RS485 9 2 21 TX GPIO5/RXT RESET# GND 22 GPIO3/RS485 18 8 1 VBUS_SENSE GPIO0/CLK 23 GPIO2/CTS# 24 GPIO1/RTS#/RS485 Pin Configuration 28-Pin Top View 4 Rev. 1E XR21B1421 Pin Assignments 24-pin QFN Pin No. Pin Name Type I/O Description 1 GPIO0/CLK 2 GND 3 USBD+ I/O USB port differential data positive input. This pin has internal pull-up resistor compliant to USB 2.0 specification. The ESD protection on this pin is +/-15 kV HBM. 4 USBD- I/O USB port differential data negative input. The ESD protection on this pin is +/-15 kV HBM. 5 VIO PWR Supply voltage for the UART and GPIO signals. The voltage range for VIO is + 1.8V to + 3.6V. In QFN28 package, the VIO is internally tied to core 3.3V. If VCC_REG is powered by 5V, VCC output 3.3V may be externally connected to VIO pin. 6 VCC PWR 3.3V power to the device, or 3.3V power output from the device when 5V power is supplied to VCC_REG pin. 3.3V output power may source up to 200 mA maximum (including the device) and should be decoupled by minimum of 4.7 uF ceramic capacitor. 7 VCC_REG PWR 5V or 3.3V power to the device. In bus-powered mode, connect VBUS power from the USB host to this pin and to the VBUS_SENSE pin. See Figure 1. In self-powered mode, connect on board 5V or 3.3V source to this pin and VBUS from the USB host to the VBUS_SENSE pin. See Figure 2 and Figure 3. USB specification requires a minimum of 1uF and a maximum of 10uF of decoupling on VBUS power. 8 VBUS_SENSE I Must be connected to VBUS power from the USB host PC. This pin is used to disable the internal pull-up resistor on the USBD+ signal when VBUS is not present in self-powered mode. In buspowered mode, connect VBUS(5V) power from the USB host to this pin and to the VCC_REG pin. In self-powered mode, connect VBUS from the USB host to this pin. This pin must be decoupled by a 4.7uF tantalum capacitor. 9 RESET# I/O OD Active low open drain output. Asserted at power on or any time device is reset by either register or USB bus reset. As an input, must be asserted for at least 15 us to force a device reset. Reset pulse width input of shorter than 15 us will have unknown effects. A weak internal pull-up resistor provides noise immunity if left unconnected. 10 NC 11 USB_STAT1 PWR General purpose I/O, or clock or pulse output. Defaults to GPIO input with internal pull-up. See “GET / SET_GPIO_CONFIG” on page 28 and “GET / SET_PIN_CONFIG” on page 41. Power supply common, ground. No Connect. MaxLinear recommends to connect this pin to the ground. OD The USB_STAT1 output pin may be used to indicate any of three USB status conditions: 1. USB_STAT1 is asserted when the USB host asserts USB reset. 2. USB_STAT1 is asserted when the USB host PC places the XR21B1421 device into the suspend state. 3. USB_STAT1 is asserted when it is not safe to draw the amount of current requested in the Device Maximum Power field of the Configuration Descriptor. a. For a low power device (