SC5826-2CS Semtech Corporation, SC5826-2CS Datasheet - Page 7

• Manufacturer Part Number: SC5826-2CS
• Description: HotSwitch USB Power Distribution Switch
• Manufacturer: Semtech Corporation

PRELIMINARY - February 18, 2000
© 2000 SEMTECH CORP.
Bus-powered hub, ganged port power
management:
A bus-powered hub distributes power and data from an
input port to downstream ports. It must supply a con-
tinuous 100mA of current to each downstream port. A
bus-powered hub must be able to switch power to
downstream ports to prevent illegal device hook-up.
Inrush current limiting is also required to prevent power
supply drooping. The circuit below utilizes the SC5826
to provide ganged port power switching, inrush current
limiting and overcurrent protection for maximum port
protection. In a ganged switch configuration, all ports
are switched simultaneously. Under fault conditions,
the USB controller will remove power to all of the
Figure 2 - Bus-powered hub with ganged port power management
TYPICAL APPLICATIONS
HotSwitch™
USB Power Distribution Switch
ganged ports. For individual port management, an ad-
ditional SC5826 may be used.
Since USB is a hot insertion and removal system, USB
ports are subject to electrostatic discharge (ESD). The
SRDA05-4 provides ESD protection on the down-
stream data and power lines. Each device will protect
two USB ports. With proper layout the port is hard-
ened to greater than 15kV, meeting the requirements
of IEC 1000-4-2. On the upstream port, the LCDA05
provides ESD protection to the above levels for one
line pair. The SC5203 (or SC5205) LDO regulator is
used to power the hub controller from the upstream
bus.
652 MITCHELL ROAD NEWBURY PARK CA 91320
SC5826
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