LTC4263

1

4263fe

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

Single IEEE 802.3af

Compliant PSE Controller

with Internal Switch

The LTC

controller for use in IEEE 802.3af compliant Power over

Ethernet systems. It includes an onboard power MOSFET,

internal inrush, current limit, and short-circuit control,

IEEE 802.3af compliant PD detection and classification

circuitry, and selectable AC or DC disconnect sensing.

Onboard control algorithms provide complete IEEE 802.3af

compliant operation without the need of a microcontroller.

The LTC4263 simplifies PSE implementation, needing

only a single 48V supply and a small number of passive

support components.

Programmable onboard power management circuitry

permits multiple LTC4263s to allocate and share power

in multi-port systems, allowing maximum utilization of

the 48V power supply—all without the intervention of a

host processor. The port current limit can be configured

to automatically adjust to the detected PD class. Detec-

tion backoff timing is configurable for either Endpoint or

Midspan operation. Built-in foldback and thermal protection

provide comprehensive fault protection.

An LED pin indicates the state of the port controlled by

the LTC4263. When run from a single 48V supply, the LED

pin can operate as a simple switching current source to

reduce power dissipation in the LED drive circuitry.

The LTC4263 is available in 14-pin 4mm × 3mm DFN and

14-pin SO packages.

Microcontroller

with Simple RC Network

Status Codes

Single-Port Fully Autonomous PSE

4263 TA01

0.1μF

100V

0.1μF

0.1μF

100V

SMAJ58A

LED

LEGACY

MIDSPAN

PWRMGT

OSC

LTC4263

ISOLATED

48V SUPPLY

+

–

TO PORT

MAGNETICS

ENFCLS

SD

OUT

OUT

ACOUT

1A

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