LTC4265 pdf datasheet (IEEE 80

The LTC®4265 is a 3rd generation Powered Device (PD)
Interface controller intended for IEEE 802.3at high power
Power-over-Ethernet (PoE) applications up to 25.5W. By
supporting 1-event and 2-event classifi cation signaling as
defi ned by IEEE 802.3, the LTC4265 can be used in a wide
range of product confi gurations. A 100V MOSFET isolates
the DC/DC converter during detection and classifi cation,
and provides 100mA inrush current for a smooth powerup
transition. The LTC4265 also includes complementary
power good outputs, an on-board signature resistor,
undervoltage/overvoltage lockout and comprehensive
thermal protection. All Linear Technology PD solutions
include a shutdown pin with signature corrupt to provide
fl exible auxiliary power options.
The LTC4265 PD interface controller can be used along
with a variety of DC/DC converter products to provide a
complete, cost effective power solution for high power
PD applications.
The LTC4265 is available in the space-saving low profi le
(4mm × 3mm) DFN package and is drop-in compatible
with the LTC4264.