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Fully USB Compliant
Support Four 5V Peripherals and
One USB 3.3V Controller
Separate Power Enables
500mA Current Limiting per
Channel
Separate Open Drain Fault
Indicator for Each Channel
3.3V Output for USB Controller
Available in 28 Pin Wide Surface
Mount and DIP
DESCRIPTION
The UCC3831 Power Controller is designed to provide a self powered
USB hub with a local 3.3V regulated voltage and four 5V regulated volt-
ages for USB ports. Each of the 5V output ports is individually enabled
for optimal port control. Each port also provides an overcurrent fault sig-
nal indicating that the port has exceeded a 500mA current limit. The
3.3V linear regulator is used to power the local USB microcontroller.
This regulator is protected with a 100mA current limit and has a logic
level enable input.
The UCC3831 can be configured to provide USB port power from a
loosely regulated voltage such as a Filament voltage internal to a moni-
tor. Pre-regulation is provided by an internal linear regulator controller
and one external logic level N-channel MOSFET. The UCC3831 can
also be configured without using the pre-regulator stage by connecting
the VREG pins to a regulated 5.5V 2A source.
The UCC3831 comes in a 28-pin wide SOIC power package optimized
for power dissipation, and is protected by internal over-temperature
shutdown mechanism, which disables the outputs should the internal
junction temperature exceed 150擄C.
APPLICATION AND BLOCK DIAGRAM
UDG-97101
11/97
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