LTC4267-1 Datasheet, PDF (1/32 Pages) Linear Technology – Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator

LTC4267-1
Power over Ethernet
IEEE 802.3af PD Interface with
Integrated Switching Regulator
FEATURES
■ _{Complete Power Interface Port for IEEE 802}^®_.3af
Powered Device (PD)
■ _{Onboard 100V, UVLO Switch}
■ _{Precision Dual Level Inrush Current Limit}
■ _{Integrated Current Mode Switching Regulator}
■ _{Onboard 25k Signature Resistor with Disable}
■ _{Programmable Classification Current (Class 0-4)}
■ _{Thermal Overload Protection}
■ _{Power Good Signal}
■ _{Integrated Error Amplifier and Voltage Reference}
■ _{Low Profile 16-Pin SSOP Package}
U
APPLICATIO S
■ _{IP Phone Power Management}
■ _{Wireless Access Points}
■ _{Security Cameras}
■ _{Power over Ethernet}
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
DESCRIPTIO
The LTC^®4267-1 combines an IEEE 802.3af compliant
Powered Device (PD) interface with a current mode switch-
ing regulator, providing a complete power solution for PD
applications. The LTC4267-1 integrates the 25k signature
resistor, classification current source, thermal overload
protection, signature disable and power good signal along
with an undervoltage lockout optimized for use with the
IEEE-required diode bridge. The LTC4267-1 provides an
increased operational current limit, maximizing power
available for class 3 applications.
The current mode switching regulator is designed for
driving a 6V rated N-channel MOSFET and features pro-
grammable slope compensation, soft-start, and constant
frequency operation, minimizing noise even with light
loads. The LTC4267-1 includes an onboard error amplifier
and voltage reference allowing use in both isolated and
nonisolated configurations.
The LTC4267-1 is available in a space saving, low profile
16-pin SSOP package.
TYPICAL APPLICATIO
Class 2 PD with 3.3V Isolated Power Supply
1" 4#.
o7
'30.
%"5"
1"*3

)%
o
o7
'30.
41"3&
1"*3

)%
o
7₁₀₃₅₁
1_7$$
4."+"
183(%
-5$
/("5&
M'
4&/4&
3_$-"44
7

3_$-"44 *₅₎36/
7_'#
4*(%*4" 1(/%
7_1035/
1₀₆₅
L
•
+
1_7$$ ⁺ _M'
M'
.*/
M'
• ^.*/
L ^4J
1_7$$
L
7
#"4
14
7
O'
7
"
$)"44*4
L
5-7
L

5"
42671f
1