SI3459 Datasheet, PDF (1/57 Pages) Silicon Laboratories – OCTAL IEEE 802.3AT POE PSE CONTROLLER

Si3459
OCTAL IEEE 802.3AT POE PSE CONTROLLER
Features
 Octal-Port Power Sourcing
 Maskable interrupt pin
Equipment (PSE) controller
 Comprehensive fault protection
 IEEE 802.3at Type I and II
circuitry includes:
compliant
Power undervoltage lockout
 Port priority shutdown control
Output current limit and short-
 Adds enhanced features for
circuit protection
maximum design flexibility:
Thermal overload detection
Per-port current and voltage
 Pin-programmable AUTO modes
monitoring
 Extended operating temp range:
PoE+ support with programmable ^{–40 to +85 °C}
current limits
 56-pin QFN package
Multi-point detection
(RoHS-compliant)
Programmable power MOSFET _{ On-chip dc-dc converter enables}
gate drive control
single-rail power operation
Configurable watchdog timer
enables failsafe operation
Applications
 IEEE Power Sourcing Equipment 
(PSE)

 Power over Ethernet Switches _
IP Phone Systems
Smartgrid Switches
Ruggedized and Industrial
Switches
Description
The Si3459 is a fully-programmable, eight-port power management
controller for IEEE 802.3 compliant Power Sourcing Equipment (PSE).
Designed for use in PSE endpoint (switches), the Si3459 integrates eight
independent ports, each with IEEE-required powered device (PD)
detection and classification functionality. In addition, the Si3459 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 Si3459 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 pin-programmable AUTO modes for autonomous operation,
without the need for a host processor. The Si3459 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 10/15
Copyright © 2015 by Silicon Laboratories
Si3459