Document
FEATURES
n IEEE 802®.3af Compliant n Operation from a Single 48V Supply n Fully Autonomous Operation without
Microcontroller n Internal MOSFET with Thermal Protection n Power Management Works Across Multiple Ports
with Simple RC Network n Precision Inrush Control with Internal Sense Resistor n Powered Device (PD) Detection and Classification n AC and DC Disconnect Sensing n Robust Short-Circuit Protection n Pin-Selectable Detection Backoff for Midspan PSEs n Classification Dependent ICUT Current Threshold n LED Driver Indicates Port On and Blinks
Status Codes n Available in 14-Pin SO and 4mm × 3mm DFN Packages
APPLICATIONS
n IEEE 802.3af Compliant Endpoint/Midspan PSEs n Single-Port or Multi-Port Power Injectors n Power Forwarders n Low-Port Count PSEs n Environment B PSEs n Standalone PSEs
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. Hot Swap and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
LTC4263
Single IEEE 802.3af Compliant PSE Controller
with Internal Switch
DESCRIPTION
The LTC®4263 is an autonomous single-channel PSE 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. Detection 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.
TYPICAL APPLICATION
+
ISOLATED 48V SUPPLY
0.1μF 100V
–
Single-Port Fully Autonomous PSE
1A
0.1μF
LTC4263
LED
VDD5
LEGACY
ENFCLS
MIDSPAN
SD
PWRMGT
VDD48
VSS
OUT
VSS
OUT
OSC
ACOUT
SMAJ58A
0.1μF 100V
TO PORT MAGNETICS
4263 TA01
4263fe
1
LTC4263
ABSOLUTE MAXIMUM RATINGS (Notes 1, 2)
Supply Voltages
VSS – VDD48 ........................................... 0.3V to –80V VDD5........................................ VSS – 0.3V to VSS + 6V Pin Voltages and Currents
LEGACY, MIDSPAN, ENFCLS, PWRMGT SD, OSC.................................. VSS – 0.3V to VSS + 6V LED....................................... VSS – 0.3V to VSS + 80V OUT, ACOUT............................................ (See Note 3)
Operating Ambient Temperature Range LTC4263C................................................ 0°C to 70°C LTC4263I............................................. –40°C to 85°C
Junction Temperature (Note 4) ............................. 125°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec)
SO..................................................................... 300°C
PIN CONFIGURATION
TOP VIEW
LED 1
14 VDD5
LEGACY 2
13 ENFCLS
MIDSPAN 3
12 SD
PWRMGT 4
15
11 VDD48
VSS 5
10 OUT
VSS 6
9 OUT
OSC 7
8 ACOUT
DE14 PACKAGE 14-LEAD (4mm s 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 43°C/W, θJC = 4.3°C/W EXPOSED PAD (PIN 15) IS VSS, MUST BE SOLDERED TO PCB
LED 1 LEGACY 2 MIDSPAN 3 PWRMGT 4
VSS 5 VSS 6 OSC 7
TOP VIEW
14 VDD5 13 ENFCLS 12 SD 11 VDD48 10 OUT 9 OUT 8 ACOUT
S PACKAGE 14-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 90°C/W, θJC = 37°C/W
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC4263CDE#PBF
LTC4263CDE#TRPBF
4263
14-Lead (4mm × 3mm) Plastic DFN
0°C to 70°C
LTC4263IDE#PBF
LTC4263IDE#TRPBF
4263
14-Lead (4mm × 3mm) Plastic DFN
–40°C to 85°C
LTC4263CS#PBF
LTC4263CS#TRPBF
4263CS
14-Lead Plastic SO
0°C to 70°C
LTC4263IS#PBF
LTC4263IS#TRPBF
4263IS
14-Lead Plastic SO
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS The l denotes the specificat.