LTC4259A| Datasheet

Datasheet preview, take a look at Datasheets before downloading (Data Sheet is available on manufacturer site)

FEATURES

LTC4259A Quad IEEE 802.3af Power over Ethernet Controller with AC Disconnect DESCRIPTIO
The LTC 4259A is a quad 48V Hot SwapTM controller designed for use in IEEE 802.3af compliant Power Sourcing Equipment (PSE). It consists of four independent ports, each with output current limit, short-circuit protection, complete Powered Device (PD) detection and classification capability, and programmable PD disconnect using AC or DC sensing. Used with power MOSFETs and passives as in Figure 1, the LTC4259A can implement a complete IEEE 802.3af-compliant PSE. The LTC4259A can operate autonomously or be controlled by an I2C serial interface. Up to 16 LTC4259As may coexist on the same data bus, allowing up to 64 powered Ethernet ports to be controlled with only two digital lines. Fault conditions are optionally signaled with the INT pin to eliminate software polling. External power MOSFETs, current sense resistors and diodes allow easy scaling of current and power dissipation levels and provide protection against voltage and current spikes and ESD events. The LTC4259A is available in a 36-pin SSOP package.
Linear Technology also provides solutions for 802.3af PD applications with the LTC4257, LTC4257-1 and LTC4267.

Controls Four Independent 48V Powered Ethernet Ports Each Port Includes: IEEE 802 .3af Compliant PD Detection and Classification Output Current Limit with Foldback Short-Circuit Protection with Fast Gate Pull-Down PD Disconnect Using AC or DC Sensing Power Good Indication Operates Autonomously or Controlled by I2CTM Serial Interface 4-Bit Programmable Digital Address Allows Control of Up to 64 Ports Programmable INT Pin Eliminates Software Polling Current and Duty Cycle Limits Protect External FETs Available in a 36-Pin SSOP Package

APPLICATIO S

IEEE 802.3af Compliant Endpoint and Midspan Power Sources IP Phone Systems DTE Power Distribution

, LTC and LT are registered trademarks of Linear Technology Corporation. HotSwap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.

TYPICAL APPLICATIO
INT SCL SDAIN SDAOUT AD0 AD1 AD2 AD3

3.3V 0.1uF

0.1uF 100V X7R

SHDN1 SHDN2 SHDN3 SHDN4

VDD

OSCIN

AUTO BYP

RESET DETECT1 DETECT2 DETECT3 DETECT4

LTC4259A

CMPD3003 4 1k 4 0.47uF 100V 4 X7R

DGND AGND VEE SENSE1 GATE1 OUT1 SENSE2 GATE2 OUT2 SENSE3 GATE3 OUT3 SENSE4 GATE4 OUT4 RS1 48V 0.1uF Q1 10k RS2 10k 10k 10k

Q2

RS3 PORT3 Q3 RS4 Q4 PORT4 S1B 4
4259A F01

RS1 TO RS4: 0.5 Q1 TO Q4: IRFM120A

Figure 1. Complete 4-Port Powered Ethernet Power Source
4259afb

U

U

U

0.1uF 100V 4

SMAJ58A 4

PORT1 PORT2

1

LTC4259A Datasheet linear Download PDF

Add this permalink to your bookmarks for future download of LTC4259A datasheet

Permalink: http://datasheet.emcelettronica.com/linear/LTC4259A

LTC4259A DATASHEET