The XR22404 is a USB 2.0, 4-port hub that can be configured for downstream device charging and is compatible with Battery Charging specification revision 1.1/1.2.
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) and downstream PHY supporting hi-speed, full-speed and low-speed (1.5 Mbps) on each of the 4 downstream ports.
The XR22404 provides ganged power control and global overcurrent sensing for the downstream ports.
The XR22404 may be operated from either 5V or 3.3V. If powered from 5V internal regulators provide 3.3V and 1.8V used internally by the device. Port activity and overall hub activity indicators provide status outputs for external LEDs. An external I2C EEPROM may be used with the XR22404 to configure USB device descriptors.
- USB 2.0 compliant interface
- Provides downstream port battery charging
- LED indicators for port, hub or charging activity
- Global port power enables
- Ganged overcurrent sensing
- Single 5V or 3.3V power supply
- Single 12MHz Crystal
Evaluation Board Schematics, Design Files & User’s Manual
- USB port expansion
- Docking stations
- POS terminals
- Factory automation and process controls
- Industrial applications
Parts & Purchasing
|Part Number||Pkg Code||RoHS||Min Temp||Max Temp||Status||Buy Now||Order Samples|
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.
Frequently Asked Questions
With a plethora of equipment with built in USB ports, USB hubs assist by expanding the number of USB ports available to plug devices into in a network. In its simplest form, a USB hub is plugged into a host computer’s USB interface. A hub has one upstream path (going back towards the host’s USB interface) and multiple downstream paths (going towards the end devices). Another downstream hub could be plugged and cascaded into the first hub and so on up to 7 tiers and 127 ports. There are limitations on USB cable length, however a USB hub can function as a repeater if more length is needed. See AN213 section 3.0 for more information.
USB is governed by industry specification http://www.usb.org/developers/docs/usb20_docs/ .
MaxLinear XR22404 and XR22414 USB hubs have 4 available downstream ports while the XR22417 provides 7. All 3 parts have a USB 2.0 compliant interface, meaning that the upstream is capable of high speed (480Mbps) and may operate at high (480Mbps) or full speed (12Mbps). Downstream can operate and high (480Mbps), full (12Mbps) or low speed (1.5Mbps).
USB 2.0 host ports provide up to 5 unit loads of 100 mA per attached peripheral device (including USB hubs). A bus powered hub, powered from USB host 5 volt VBUS, can supply a maximum of 1 unit load on each of its downstream ports. For example, a 4-port hub must be able to supply 4 x 100 mA or 400 mA total and is also allotted 100 mA for its own power requirements. A hub with more than 4 downstream ports cannot be bus powered.
Conversely, a self-powered hub is powered by an outside power source. It is restricted in the number of downstream ports and the power to those ports only by the power from the external source. A self-powered hub should typically be able to provide a minimum of 5 unit loads per downstream port.
MaxLinear has a number of USB 2.0 hub products. The 4-port XR22404, XR22414 and 7-port XR22417 all support self-powered mode while XR22404 and XR22414 can also be bus-powered. The XR22404 can provide battery charging on its downstream ports, but must be in self-powered mode to do so.
STT (Single Transaction Translator) is where one TT splits transactions and polls round robin to translate to multiple downstream peripheral devices, such as in the case of the XR22404 that shares the bandwidth. MTT (Multiple Transaction Translator) is where several are provided. The XR22414 provides one for each of the 4 downstream ports, while the XR22417 provides one for each of the 7 downstream ports. A dedicated TT for the downstream ports provides each the highest bandwidth capability, 12Mbps each in the case of full speed.
Either an individual or ganged power mode can be employed. In ganged mode all ganged ports are monitored by one power monitoring device and global current sensing is used. However in an over-current condition, all ganged ports are disabled. In individual mode each downstream port monitors over-current and can disable power independently. XR22404 uses ganged power mode and global overcurrent sensing. XR22414 can be configured for either ganged or individual power mode as shown in its datasheet. XR22417 uses individual power mode.
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.
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.
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.