LTC4266C_15 Datasheet, PDF (1/30 Pages) Linear Technology – Quad PoE/PoE/LTPoE PSE Controller

FEATURES
nn _{Four Independent PSE Channels}
nn _{Compliant with IEEE 802.3at Type 1 and 2}
nn _{Low Power Dissipation}
nn _{0.25Ω Sense Resistance Per Channel}
nn _{Very High Reliability 4-Point PD Detection}
nn _{2-Point Forced Voltage}
nn _{2-Point Forced Current}
nn _{High Capacitance Legacy Device Detection}
nn _{1MHz I}²_{C Compatible Serial Control Interface}
nn _{Midspan Backoff Timer}
nn _{Supports 2-Pair and 4-Pair Output Power}
nn _{Available in Multiple Power Grades}
nn _{LTC4266A-1: LTPoE++™ 38.7W}
nn _{LTC4266A-2: LTPoE++ 52.7W}
nn _{LTC4266A-3: LTPoE++ 70W}
nn _{LTC4266A-4: LTPoE++ 90W}
nn _{LTC4266C: PoE 13W}
nn _{Available in 38-Lead 5mm × 7mm QFN Package}
APPLICATIONS
nn _{LTPoE++ PSE Switches/Routers}
nn _{LTPoE++ PSE Midspans}
nn _{IEEE 802.3at Type 1 PSE Switches/Routers}
nn _{IEEE 802.3at Type 1 PSE Midspans}
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
LTPoE++ and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
LTC4266A/LTC4266C
Quad PoE/PoE+/LTPoE++
PSE Controller
DESCRIPTION
The LTC^®4266A is a quad power sourcing equipment (PSE)
controller capable of delivering up to 90W of LTPoE++
power to a compatible LTPoE++ powered device (PD). A
proprietary detection/classification scheme allows mutual
identification between a LTPoE++ PSE and LTPoE++ PD
while remaining compatible and interoperable with existing
Type 1 (13W) and Type 2 (25.5W) PDs. The LTC4266A
feature set is a superset of the popular LTC4266. These
PSE controllers feature low R_ON external MOSFETs and
0.25Ω sense resistors which are especially important at
the LTPoE++ current levels to maintain the lowest possible
heat dissipation.
The LTC4266C targets fully automatic PSE systems power-
ing Type 1 (up to 13W) PDs.
Advanced power management features include: 14-bit
current monitoring ADCs, DAC-programmable current
limit, and versatile quick shutdown of preselected ports.
Advanced power management host software is available
under a no-cost license. PD discovery uses a proprietary
dual-mode 4-point detection mechanism ensuring excellent
immunity from false PD detection. The LTC4266 includes
an I²C serial interface operable up to 1MHz.
The LTC4266 is available in multiple power grades allow-
ing delivered PD power of 13W, 25.5W, 38.7W, 52.7W,
70W and 90W. These controllers are available in a 38-lead
5mm × 7mm QFN package.
TYPICAL APPLICATION
Complete 4-Port Ethernet High Power Source
10Ω
3.3V
+ ^SMAJ5.0A
10µF
10Ω
+
C_BULK
–54V
SMAJ58A
TVSBULK
V_DD ^{AD0 AD1 AD2 AD3}
0.1µF
DGND
SHDN1
SHDN2
SHDN3 SHDN4
LTC4266
AUTO MSD
RESET
MID SDAIN SCL
SDAOUT
INT
AGND
1µF
100V
V_EE SENSE1 GATE1 OUT1 SENSE2 GATE2 OUT2 SENSE3 GATE3 OUT3 SENSE4 GATE4 OUT4
0.22µF 100V
S1B
×4
×4
For more information www.linear.com/LTC4266A
S1B
×4
–54V
PORT1
PORT2
PORT3
PORT4
4266AC TA01
4266acfd
1