SI3454 Datasheet, PDF (1/57 Pages) Silicon Laboratories – QUAD IEEE 802.3AT POE PSE CONTROLLER

Si3454
QUAD IEEE 802.3AT POE PSE CONTROLLER
Features
 Quad-Port Power Sourcing
Equipment (PSE) controller
 IEEE 802.3at Type I and II
compliant
 Port priority shutdown control
 Adds enhanced features for
maximum design flexibility:
Per-port current and voltage
monitoring
PoE Plus support with
programmable current limits
Multi-point detection
Programmable power MOSFET
gate drive control
Configurable watchdog timer
enables failsafe operation
 Maskable interrupt pin
 Comprehensive fault protection
circuitry includes:
Power undervoltage lockout
Output current limit and short-
circuit protection
Thermal overload detection
 Supports pin-selectable
AUTO mode
 Extended operating temp range:
–40 to +85 °C
 5x7 mm 38-pin QFN package
(RoHS-compliant)
 On-chip dc-dc converter enables
single-rail power operation
Applications
 IEEE Power Sourcing Equipment  IP Phone Systems
(PSE)
 Smartgrid Switches
 Power over Ethernet (PoE)
Switches
 Ruggedized and Industrial
Switches
Description
The Si3454 is a fully-programmable, four-port power management
controller for IEEE 802.3 compliant Power Sourcing Equipment (PSE).
Designed for use in PSE endpoint (switches), the Si3454 integrates four
independent ports, each with IEEE-required powered device (PD)
detection and classification functionality. In addition, the Si3454 features a
fully-programmable architecture that enables powered device (PD)
disconnect using a dc sense algorithm, a robust multipoint detection
algorithm, software-configurable per-port current and voltage monitoring,
and programmable current limits to support the IEEE 802.3at standard.
Intelligent protection circuitry includes input undervoltage detection,
output current limit, and short-circuit protection. The Si3454 operates by
host processor control through a three-wire, I²C-compatible serial
interface. Independent serial data input and output pins enable high-
voltage isolation through external isolators. An interrupt pin is used to
alert the host processor of various status and fault conditions. The device
also supports a pin-selectable AUTO mode for autonomous operation,
without the need for a host processor. The Si3454 also features an on-
chip dc-dc converter for creating the digital voltage rail from the PoE
voltage, thus enabling single-rail power operation.
Ordering Information:
See page 49.
Rev. 1.1 9/15
Copyright © 2015 by Silicon Laboratories
Si3454