XR21B1411

增强型单通道全速USB通用异步收发器

Description

 

XR21B1411 (B1411) 是一款增强型、带USB接口的通用异步收发器。其USB接口完全符合全速USB 2.0标准并支持12Mbps的USB数据传输速率。USB接口还支持USB挂起、恢复和远程唤醒操作。
B1411在一个内部时钟控制下工作,该内部时钟频率可调至6、12、24或48MHz。因此,和上一代UART不同,B1411无需外部晶振/振荡器。借助内部时钟,内置的分数波特率生成器可以精确地生成最高为12Mbps的任何波特率。
B1411具有128字节发送FIFO和384字节接收FIFO,有助于优化各种应用中的整体数据吞吐量。自动收发方向控制功能,从硬件和软件方面上简化了半双工RS-485的应用。必要时,在多点(9位)模式下自动半双工收发器控制功能可进一步简化常见的多点RS-485的应用。
B1411的板载OTP可以借助USBD+ / USBD-引脚,对厂商和产品的ID、总线/自供电模式、远程唤醒支持或最高功耗值、以及默认波特率设置进行编程设计。
B1411为5V单电源供电,提供16-pin QFN封装。
XR21B1411支持Windows 7、2000、XP、Vista和CE、以及Linux和Mac等系统的软件驱动程序。
如需任何有关UART的技术支持或获取本产品的IBIS模型,请电邮Exar UART技术支持组Exar's UART Technical Support group.
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Features

  • USB D+/USB D-引脚提供 ±15kV HBM ESD静电保护
  • 接口符合USB 2.0规范
    • 支持12Mbps的USB全速数据传输速率
    • 支持USB挂起、恢复和远程唤醒操作
  • 增强型UART 特性
    • 数据传输速率高达12 Mbps
    • 分数波特率发生器
    • 128字节 TX FIFO
    • 384字节RX FIFO
    • 支持7、8或9位数据位
    • 支持1或2 位停止位
    • Odd, even, mark, space or no parity
    • 自动硬件流控制(RTS/CTS或DTR/DSR)
    • 自动软件流控制(Xon/Xoff)
    • 多点模式
    • 自动收发器控制
    • 半双工模式
    • 可选择的GPIO或Modem I/O
  • 带可编程时钟分频器的48MHz内部时钟,最低可调至6MHz
  • 5V单电源供电
  • 16-pin QFN封装
  • 虚拟COM端口驱动,支持以下操作系统
    • Windows 7, 2000, XP 以及Vista
    • Windows CE 4.2, 5.0, 6.0
    • Linux
    • Mac

Application

  • 便携式设备
  • 外部转换器(加密狗)
  • 电池供电设备
  • 蜂窝数据设备
  • 工厂自动化和过程控制
  • 工业应用



       Exar I/O Lab - Easy-to-use Online Programming Design Tool

Design Tools

Evaluation Hardware and Software
Operating System Driver Version Release Date File
Windows XP, Vista, 7, 8, 8.1, 10 2.5.0.0 九月 2018
Linux 3.6.x and Newer 1C 一月 2017
Windows XP, Vista, 7, 8 2.2.5.0 三月 2016
Android Application 1C 十一月 2015
Linux 2.6.18 to 3.4.x 1A 一月 2015
Sample USB UART GUI 1.0.9.2 十二月 2013
Mac 1.0.4 十月 2013

包装

Pkg Code Details Quantities Dimensions PDF
QFN16 3x3
  • JEDEC Reference: MO-220
  • MSL Pb-Free: L1 @ 260ºC
  • MSL SnPb Eutectic:
  • ThetaJA: 36.4ᵒC
  • Bulk Pack Style: Tray
  • Quantity per Bulk Pack: 490
  • Quantity per Reel: 3000
  • Quantity per Tube: n/a
  • Quantity per Tray: 490
  • Reel Size (Dia. x Width x Pitch): 330 x 12 x 8
  • Tape & Reel Unit Orientation: Quadrant 1
  • Dimensions: mm
  • Length: 3.0
  • Width: 3.0
  • Thickness: 1.00
  • Lead Pitch: 0.5

Parts & Purchasing

Part Number Pkg Code RoHS Min Temp Max Temp Status Buy Now Order Samples
XR21B1411IL16-B1-F OBS Suggested:
XR21B1411IL16-F
XR21B1411IL16-B2-F OBS Suggested:
XR21B1411IL16-F
XR21B1411IL16TR-F QFN16 3x3 -40 85 Active
XR21B1411ILTR-B1-F OBS Suggested:
XR21B1411IL16TR-F
XR21V1410IL16-F QFN16 3x3 -40 85 Active
XR21B1411IL-0A-EB Board Active
Show obsolete parts
Part Status Legend
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.

Quality Documents

Part NumberMDSREACHReL
XR21B1411IL16-D2-FDownload
XR21V1410IL16-FDownload
XR21B1411Download
Additional Quality Documentation may be available, please contact customersupport@exar.com.
Distribution Date Description File
07/04/2018 Product Discontinuation Notice PDN 18-0624-01-1033.pdf
07/11/2017 Product Discontinuation Notification Product Discontinuation Notice 17-0623-02 r-1033.pdf
06/29/2017 Unify Package 16L 3X3 QFN lead length (L) range from 0.35-0.45 mm to 0.30-0.50 mm and add Pin1 indication. PCN 17-0623-01-1033.pdf
02/14/2017 Qualification of alternate assembly subcon, GREATEK, Taiwan. PCN 17-0102-01 Greatek-1033.pdf
01/31/2017 Addition of qualified 12 inch wafer processing line in Global Foundries, in addition to the currently qualified 8 inch wafer processing. Note: Reliability report will be available February 17, 2017. PCN 16-0731-01-01 12 inch Global Foundries-1033.pdf
01/27/2017 Qualification of alternate assembly subcon, ANST, China. PCN 16-1145-04-01 ANST-1033.pdf
05/16/2016 XR21B1411C has been qualified and production released. Rev C has improved USB differential noise performance, replacing Rev B as production. The products listed above are affected. Switchover will be identified by date code. PCN 16-0519-01-01-1033.pdf
04/02/2014 Qualified UTAC Thailand for assembly using copper wire or gold wire bonding assembly, in addition to the current qualified gold wire bonding assembly sites, Unisem Batam and UTAC China. Material change and alternate assembly site. PCN_13-0729-02-1033.pdf
10/03/2013 Product Discontinuation Notification Discontinued. PDN_13-1003-01-1033.pdf
08/10/2011 Material change and a new assembly & test supplier (ASE, Kunshan). Business consolidation. PCN_11-0724-01-1033.pdf

Frequently Asked Questions

For some UARTs, Microsoft certified drivers are available for Windows Operating System and can be downloaded via Windows Update. These drivers and others, including for Linux and other Operating Systems can be found by visiting https://www.exar.com/design-tools/software-drivers Please note Software Driver Use Terms.

 

 
You can also get to this link by going to the exar.com website, clicking on Support (in black bar near top of page), then click on Design Tools, then under Evaluation Hardware and Software (towards right of page) click on Software Drivers.
 
 

Click on the version link under Driver Version of the desired type of UART, part number and operating system. A zip file is downloaded which contains a ReadMe file with instructions.

Links to datasheets and product family pages are in the software driver table for easy reference. 
No, Auto RTS and Auto CTS are independent. Auto RTS is toggled by the UART receiver. Auto CTS is monitored by the UART Transmitter.
No, Auto RTS and Auto CTS will work normally without the interrupts enabled.
No, software flow control characters are not loaded into the RX FIFO.
Auto RS485 Half-Duplex Control feature overrides the Auto RTS flow control feature if both features use the RTS# output pin. Both features can only be used simultaneously if the Auto RS485 control output is not the RTS# output. For some UARTs, the Auto RS485 control output is not the RTS# output.
The polarity of the RS485 control output varies from one UART to another. For some UARTs, an inverter may be required. Some of the newer UARTs have register bits that can change that polarity of the RS485 control output.
All of the UARTs that have the IR mode supports up to 115.2Kbps as specified in IrDA 1.0. The newer I2C/SPI UARTs can support up to 1.152Mbps as specified in IrDA 1.1.

Find the product page of the part that you want to get an evaluation board for and click on Parts & Purchasing. Example:

 

Find the icons under Buy Now or Order Samples:

 
 

Click on the Buy Now icon and see who has stock and click on the Buy button:

 
 
 

Alternatively, you can click on the Order Samples

 
 

If the icons are missing, then contact Customer Support.

The best way to determine this is to go to exar.com and type the part into the search function. At or near the top of the results you should see something that looks like
 
 

In this example, we looked for XRA1201. When you hover over it, it will turn grey and you can click anywhere in the grey box. This brings you to the product page. For example:

 
 

Click on Parts & Purchasing, highlighted in yellow above. The screen changes to:

 

Notice the status column and the “Show obsolete parts” link:

 

A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers:

 
 

Another method to find out if a part is OBS or EOL is to click on SUPPORT:

 

And then Product Change Notifications

 
 

Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:

 
 

If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.

Connect the USB data pins directly to the host or upstream hub. Connections should be impedance controlled to 90 ohms differential with short traces and no stubs. Connecting any other components that are not high impedance (series or shunt resistance, capacitance or inductance) will corrupt the USB data signaling and can prevent communication between the host and device. ESD protection diodes may be used and some EMI filters may also have only a slight impact on impedance but should be demonstrated for compliance with USB 2.0 devices. See Application Notes AN202 (USB UART Board Design Recommendations and Considerations for USB Compliance), section 2.0 Design Considerations  for more. 

1. Native drivers: Native drivers may be found in all major OS such as Windows, Linux, and Max OSX. Typically these drivers will be automatically loaded. In some cases, these are basic drivers and may have limitations on advanced device functionality, however. USB HID, Hub and CDC-ACM drivers are examples of native drivers. The CDC-ACM driver be used with our CDC-ACM class USB UARTs, but has limited functionality.

 

2. MaxLinear custom drivers: MaxLinear custom drivers may be used to support additional functionality in MaxLinear devices. For example, the MaxLinear custom driver for USB UARTs overcomes the limitations of the native CDC-ACM driver. See https://www.exar.com/design-tools/software-drivers for a list of and access to the drivers that we currently have. In some cases, the MaxLinear driver can also be customized, or source code can be provided after executing a Software License Agreement.

Yes: Go to the product page (XR22804 example below), click on the documentation tab on left, click on “Sample USB UART GUI” under Software:

 
It depends on the baud rate. For example, for a start bit, 8 data bits, no stop bit and 1 stop bit, the maximum baud rate deviation is 4.76%. For more information, see https://www.exar.com/appnote/dan108.pdf
Most UARTs use RTS#, however in addition to using the RTS# output as the Auto RS485 control output, the XR21B1420/1421/1422/1424 can use the DTR# output as the Auto RS485 control output.

The following lines of code must be modified in the xr_usb_serial_hal.c file in the xr_usb_serial_set_flow_mode function at the end of the function:

 

Change from:

xr_usb_serial_set_reg(xr_usb_serial, xr_usb_serial->reg_map.uart_flow_addr, flow);

xr_usb_serial_set_reg(xr_usb_serial, xr_usb_serial->reg_map.uart_gpio_mode_addr, gpio_mode);

 
For active low TX, change to:

xr_usb_serial_set_reg(xr_usb_serial, xr_usb_serial->reg_map.uart_flow_addr, 0x0);

xr_usb_serial_set_reg(xr_usb_serial, xr_usb_serial->reg_map.uart_gpio_mode_addr, 0x3);

 

For active high TX, change to:

xr_usb_serial_set_reg(xr_usb_serial, xr_usb_serial->reg_map.uart_flow_addr, 0x0);

xr_usb_serial_set_reg(xr_usb_serial, xr_usb_serial->reg_map.uart_gpio_mode_addr, 0xB);

All of MaxLinear / Exar's USB UARTs are CDC class / CDC-ACM compliant, except for XR21B1421 which is an HID class device. This means they can use a native CDC driver. All major OS have native CDC drivers, except Windows prior to Windows 10.

None of the MaxLinear / Exar USB UARTs require their custom driver, however they will have certain limitations when not using it. The native CDC driver is not capable of accessing the internal memory map of any device. As a result, when using the native CDC driver, the device “defaults” to a particular configuration. The main implications of this default configuration are that hardware RTS/CTS flow control is enabled and that other settings / advance settings are not configurable. Some devices, for example the XR21B1411 which has an internal OTP memory, can be programmed to change this default configuration, but the configuration cannot be changed “on the fly”.

1.  Enter root privileges: sudo -i
2.  Enter admin password.
3.  Edit /etc/modules file.  Append xr_usb_serial_common to the end of the file.
4.  Build the Exar/MxL driver from the folder using "make", confirm that the xr_usb_serial_common.ko file is successfully created.
5.  Run command: uname -r
This will return the kernal version currently in use. 
6.  Copy the resulting xr_usb_serial_common.ko to /lib/modules/2.6.38.8-generic in the above path with the kernal version that was returned in step 5.
7.  Run depmod.
8.  Reboot. 
9.  Connect the Exar/MxL USB UART.  Using ls/dev/tty* confirm /dev/ttyUSBn ports (Exar driver loaded) for Exar/MxL USB UART.
10. Connect another CDC device (not Exar/MxL), and confirm both /dev/ttyUSBn and /dev/ACMn ports. 
The maximum allowed bus-powered suspend current is 2.5mA per device function. The device function may not be the same as the IC, as there may be multiple device functions per IC. See the individual datasheet for a list of device functions. For example, the XR22804 has 8 device functions: an embedded hub, the Ethernet MAC and Phy, 4 UARTs, I2C controller and EDGE controller. Therefore, the XR22804 maximum allowed bus-powered suspend current is 8 x 2.5mA or 20mA. However, power used by all supporting XR22804 external components that use power from the USB host VBUS power must be included in the suspend current.
The OTP can be programmed to modify various USB configuration descriptors such as Vendor ID, Product ID, Device Attributes and maximum power consumption. See Application Note AN202 (USB UART board Design Considerations for USB Compliance), section 2.3 External EEPROM ot on-chip OTP for more. The OTP can also be programmed to change default register values, which can be found in the individual datasheets.
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