XR22417 Datasheet, PDF (13/17 Pages) Exar Corporation – USB 2.0 7-Port Hub

XR22417
Applications Information (Continued)
Power Control and Overcurrent Protection
In the LQFP-64 package, the XR22417 OVCn# pins monitor overcurrent conditions for each port and individual PWRn#
pins enable power to devices connected to each downstream port. Figure 5 depicts downstream ports 1-4 using individual
power and overcurrent protection.
NOTE:
Ports 5-7 are unused in this example. If used can duplicate the monitor and control using the XRP2528.
3.3V
5V
OVC1#
OVC2#
OVC3#
OVC4#
OVC5#
OVC6#
OVC7#
XR22417
PWR1#
PWR2#
PWR3#
PWR4#
PWR5#
PWR6#
PWR7#
ENA
OUTA
FLGA
IN
FLGB ^XRP2528 GND
ENB
OUTB
RSETA
RSETB
ENA
OUTA
FLGA
IN
FLGB ^XRP2528 GND
ENB
OUTB
RSETA
RSETB
To VBUS of Port 1
To VBUS of Port 2
To VBUS of Port 3
To VBUS of Port 4
Figure 5. LQFP-64 Individual Power Control and Overcurrent Mode
USB Hub Drivers
All operating systems provide a native USB hub device driver for the XR22417 device to operate. No other device drivers
are necessary for the XR22417.
Regulated 3.3V Power Output
The XR22417 internal voltage regulator provides 3.3 VDC output power from 5V input, which can be utilized by
other circuitry. Refer to Electrical Characteristics on page 2 for maximum power capability.
REV1A
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