The XR22804 is a Hi-Speed USB 2.0 compound device with an embedded hub and 7 downstream USB functions: 10/100 Ethernet MAC and PHY, 4 UARTs, multi-master capable I2C controller, and an Enhanced Dedicated GPIO Entity (EDGE) controller.
The upstream USB interface has an integrated USB 2.0 PHY and device controller that is compliant with both Hi-Speed (480Mbps) and Full-Speed (12Mbps) USB 2.0. The vendor ID, product ID, power mode, remotewakeup support and maximum power consumption are amongst the values that can be programmed using the on-chip One-Time Programmable (OTP) memory.
The Ethernet 10/100 MAC and PHY are compliant with IEEE 802.3 and supports auto-negotiation, auto-MDIX, checksum offload, auto-polarity correction in 10Base-T and remote wakeup capabilities.
The enhanced UART has a maximum data rate of 15 Mbps. Using a fractional baud rate generator, any baud rate between 300 bps and 15 Mbps can be accurately generated. In addition, the UART has a large 1024-byte TX FIFO and RX FIFO to optimize the overall data throughput for various applications. The automatic RS485 control feature simplifies both the hardware and software for half-duplex RS-485 applications. If required, the multidrop (9-bit) mode feature further simplifies typical multidrop applications by enabling / disabling the UART receiver depending on the address byte received.
The multi-master capable I2C controller and EDGE controller (up to 32 GPIOs) can be accessed via the USB HID interface. The EDGE pins or I2C interface can be used for controlling and monitoring other peripherals. Up to 2 EDGE pins can be configured as a PWM generator.
- USB 2.0 Compliant Interface
- 10/100 Ethernet MAC and Phy
- Enhanced UART
- Half-Duplex Mode
- I2C Multi-master
- Enhanced Dedicated GPIO Entity (EDGE)
- Single +5.0V Power Supply Input
- Regulated +3.3V Output Power
- Single 25MHz Crystal
- ±15kV HBM ESD Protection on USB data pins
- ±8kV HBM ESD Protection on all other pins
- USB to Ethernet Dongles
- POS Terminals
- Test Instrumentation
- Factory Automation and Process Controls
- Industrial Applications
|Operating System||Driver Version||Release Date||File|
|Linux 3.6.x and Newer||1D||September 2021|
|Sample USB UART GUI (Serial Test App)||188.8.131.52||July 2021|
|Windows XP, Vista, 7, 8, 8.1, 10||184.108.40.206||December 2019|
|Windows 10||220.127.116.11||June 2018|
|Windows XP, Vista, 7||18.104.22.168||December 2017|
|XRUSB1 for Win XP SP3 and newer||22.214.171.124||March 2016|
|Android Application||1C||November 2015|
|Linux 2.6.18 to 3.4.x||1A||January 2015|
Parts & Purchasing
|Part Number||Pkg Code||Min Temp||Max Temp||Status||Buy Now||Order Samples|
|XR22804IL56-F||QFN56 8x8 OPT1||-40||85||Active||Order|
|XR22804IL56TR-F||QFN56 8x8 OPT1||-40||85||OBS||
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 & Environmental Data
|Part Number||RoHS | Exempt||RoHS||Halogen Free||REACH||MSL Rating / Peak Reflow||Package|
|XR22804IL56-F||N||Y||Y||Y||L3 / 260ᵒC||QFN56 8x8 OPT1|
Click on the links above to download the Certificate of Non-Use of Hazardous Substances.
Search our list of FAQs for answers to common technical questions.
For material content, environmental, quality and reliability questions review the Quality tab or visit our Quality page.
For ordering information and general customer service visit our Contact Us page.
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.
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.
USB peripheral devices may operate in bus or self-powered modes. In bus powered mode, the peripheral device is powered by the USB host 5V VBUS power either directly, or for example through a voltage regulator that might provide a regulated 3.3V to the device from the 5V VBUS input. In self-powered mode, power to the peripheral device comes from another source other than the USB host VBUS. For example, power might come from an AC to DC converter.
MaxLinear USB to serial / UART(s), USB hubs and USB to Ethernet devices all comply fully to USB standards and are fully USB compliance tested. One USB compliance test ensures that self-powered peripheral devices do not have “back voltage” when disconnected from the USB host, on either the USB data signals (USBD+ / USBD-) or the VBUS power itself.
All MaxLinear USB UARTs, hubs and USB to Ethernet devices are USB full speed or high-speed devices. As such, they have an internal pull-up on the USBD+ signal to “advertise” their speed rating. The VBUS_SENSE pin on these devices must be connected to VBUS from the host, or upstream device if that is not the host, such that the device “senses” the disconnection from the host or upstream device. The default power mode advertised to the USB host for all USB UARTs and USB to Ethernet devices is bus powered mode. Self-powered mode can be programmed in either the internal OTP memory or external EEPROM for self-powered mode. For MaxLinear hubs, an external pin controls the power mode advertised to the USB host, except the XR22417 which must always be operated in self-powered USB mode.
Yes: Go to the product page (XR22804 example below), click on the documentation tab on left, click on “Sample USB UART GUI” under Software:
In this example, we looked for XRA1201. Click on part number header or on the link at the bottom of the result. This brings you to the product page. For example:
Click on Parts & Purchasing, highlighted with the blue arrow 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, the legend still present:
Another method to find out if a part is OBS or EOL is to click on SUPPORT at the top:
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.
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.
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”.
For thermal and ESD benefits, the following PCB design is recommended to provide thermal and electrostatic paths:
1. Design the PCB to conduct heat away from the device using thermal vias under the QFN IC to the digital ground plane.
2. Mount the metal shells of the USB and Ethernet connectors to a separate Chassis / Earth ground.
3. Place the chassis / earth ground metal on one PCB layer, digital ground on another PCB layer and connect through a zero ohm resistor located away from sensitive electronic devices as much as possible.
4. Place a large metal trace for the Earth ground all the way surrounding the PCB, except under the Ethernet connector.
As an example, see the schematic and an example PCB layout for the XR22800 Evaluation Board below:
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.
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