LTC4257_15 datasheet(5/20 Pages) LINER

Part #	LTC4257

Description	IEEE 802.3af PD Power over Ethernet Interface Controller

Download	20 Pages

Scroll/Zoom	100%

Manufacturer	LINER [Linear Technology]

Direct Link	http://www.linear.com

Logo

5 / 20 page

LTC4257

5

4257fb

NC (Pin 1): No Connect.

RCLASS (Pin 2): External Class Select Input. Used to set the

current the LTC4257 maintains during classification. Con-

nect a resistor between RCLASS and VIN (see Table 2).

NC (Pin 3): No Connect.

VIN (Pin 4): Power Input. Tie to system – 48V through the

input diode bridge.

VOUT (Pin 5): Power Output. Supplies –48V to the PD load

through an internal power MOSFET that limits input cur-

rent. VOUT is high impedance until the input voltage rises

above the turn-on UVLO threshold. Above the UVLO

threshold the output is current limited to 350mA.

PWRGD (Pin 6): Power Good Output, Open-Drain. Signals

that the LTC4257 MOSFET is fully on. Low impedance

indicates power is good. PWRGD is high impedance

during detection, classification and in the event of a

thermal overload. PWRGD is referenced to VIN.

NC (Pin 7): No Connect

GND (Pin 8): Ground. Tie to system ground and to power

return through the input diode bridge.

PI FU CTIO S

BLOCK DIAGRA

4257 BD

VIN

BOLD LINE INDICATES HIGH CURRENT PATH

VOUT

–

+

8

5

4

NC 3

RCLASS 2

NC

PWRGD

GND

7

NC

1

6

CONTROL

CIRCUITS

INPUT

CURRENT

LIMIT

350mA

POWER GOOD

CLASSIFICATION

CURRENT SOURCE

1.237V

EN

0.3

Ω

–

+

EN

25k SIGNATURE

RESISTOR

Similar Part No. - LTC4257_15

Manufacturer	Part #	Datasheet	Description
Linear Technology	LTC4257-1	267Kb / 20P	Power over Ethernet Interface Controller with Dual Current Limit
	LTC4257-1	616Kb / 32P	12-Port PoE/PoE/LTPoE PSE Controller
	LTC4257-1	671Kb / 28P	Single PoE PSE Controller High Capacitance Legacy Device Detection
	LTC4257-1	389Kb / 32P	12-Port PoE/PoE/LTPoE PSE Controller
	LTC4257-1	504Kb / 42P	Synchronous No-Opto Flyback Controller

More results

Similar Description - LTC4257_15

Manufacturer	Part #	Datasheet	Description
Linear Technology	LTC4257	263Kb / 20P	IEEE 802.3af PD Power over Ethernet Interface Controller
Maxim Integrated Produc...	MAX5940	248Kb / 15P	IEEE 802.3af PD Interface Controller For Power-Over-Ethernet 19-2991; Rev 2; 2/06
	MAX5940	248Kb / 15P	IEEE 802.3af PD Interface Controller For Power-Over-Ethernet Rev 2; 2/06
	MAX5940A	295Kb / 15P	IEEE 802.3af PD Interface Controller For Power-Over-Ethernet Rev 0; 10/03
Linear Technology	LTC4267CDHC-3	1Mb / 32P	Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator
	LTC4267	1Mb / 32P	Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator
	LTC4267-1	903Kb / 32P	Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator
Linear Integrated Syste...	LTC4267IGN-3	1Mb / 32P	Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator
Linear Technology	LTC4267-3	715Kb / 32P	Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator
Microsemi Corporation	PD70101	831Kb / 20P	Power Over Ethernet 802.3af/at PD Controller Rev.2.0, 17-Jan-2017

More results

LTC4257 Datasheet(PDF) 5 Page - Linear Technology

LTC4257 Datasheet(HTML) 5 Page - Linear Technology

Similar Part No. - LTC4257_15

Similar Description - LTC4257_15

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Download

Link URL