SI3480 Datasheet, PDF (1/14 Pages) List of Unclassifed Manufacturers – POWER MANAGEMENT CONTROLLER

Si3480
Si3480 POWER MANAGEMENT CONTROLLER
Features
 Enables use of a smaller power  Pin programmable for overall
supply for a 4 or 8 port PoE
power supply capacity, port
system
power level, port priority, and
 Self-contained solution operates ^{detection timing}
without the need for a host for  LED indication of port status and
unmanaged operation
overall power consumption
No software required
 20-pin Quad flat package
No data isolation required
(4x4 mm)
 Fully compliant with IEEE 802.3
4x4 mm PCB footprint; RoHS
clause 33 for Power over Ethernet
compliant
including the 802.3at amendment ^{ Extended operating temperature}
for higher power (30 W category 2 ^{range (–40 to +85 °C)}
ports)
Description
The Si3480 is a power manager intended for use with the Si3452 Power
over Ethernet (PoE) controller. The Si3480 enables the use of a smaller,
lower cost, and more efficiently-utilized power supply in an unmanaged
PoE Power Sourcing Equipment (PSE) system.
The Si3452 is capable of delivering over 30 W per port, which means that,
in a typical 8-port system, a 240 W power supply would have to be used
to avoid overload. Typically, not all ports are used at full power; so, a
smaller power supply in the range of 30 to 150 W can be used along with
the Si3480 power management controller.
The Si3480 power management controller is pin programmed. The pins
are used to set the power supply capacity, the number of low power
(category 1, 15.4 W), and high power (category 2, 30 W) ports, the port
priority, and the detection timing (Alternative A or Alternative B). The
Si3480 uses the real time overload and current monitoring capability of
the Si3452 to manage power for up to eight ports. Power management is
based on actual consumption rather than mere classification in order to
supply power to the greatest number of ports.
The Si3480 also provides LED drive to indicate port status and drive an
LED bar graph display to indicate the power supply capacity in use. If a
port is denied power due to power supply capacity limitations, the LED
indicators provide a simple and intuitive indication, helping a user
recognize and correct the overload situation by rebalancing loads or
adding mid-span power injectors to ports that would not otherwise be
powered. In case of a port overload, the port is easily re-enabled by
disconnecting the Powered Device (PD) and then reconnecting the PD
after correcting the overload situation.
Ordering Information:
See Ordering Guide on page 9.
Pin Assignments
(Top View)
SDA 1
GND 2
VDD 3
RST 4
NC 5
15 PRIOCFG
14 ALTCFG
13 LED8
12 LED7
11 LED6
Rev. 1.0 7/10
Copyright © 2010 by Silicon Laboratories
Si3480