LTC4263IDE-1#TRPBF Linear Technology, LTC4263IDE-1#TRPBF Datasheet - Page 15

• Manufacturer Part Number: LTC4263IDE-1#TRPBF
• Description: IC IEEE 803.2AF CNTRLR 14-DFN
• Manufacturer: Linear Technology
• Type: Power Over Ethernet (PoE)r

Specifications of LTC4263IDE-1#TRPBF

• Applications: Power Interface Switch for Power Over Ethernet (PoE) Devices
• Voltage - Supply: 48V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-DFN
• Current - Supply: 1mA
• Interface: IEEE 802.3af
• Controller Type: Power Sourcing Equipment Controller (PSE)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
2.2μs. During the 2.2μs that the LED pin is pulled low, cur-
rent ramps up in the inductor, limited by R
completes the circuit by allowing current to circulate while
the LED pin is open circuit. Since current is only drawn
from the power supply 6% of the time, power dissipation
is substantially reduced.
When V
signal is disabled and the LED pin will pull down continu-
ously when on. In this mode, the LED can be powered from
the 5V supply with a simple series resistor.
Figure 7. LED Drive Circuit with Single 48V Supply
DD5
DS1608C-106
10mH, 21mA
COILCRAFT
V
Table 1. Port Status and LED Flash Codes
DD48
is powered from an external supply, the PWM
PORT STATUS
Non-Powered Device
0Ω < R
Port Open
R
Port On
25kΩ
Low Signature Resistance
300Ω < R
High Signature Resistance
33kΩ < R
Port Overload Fault
V
SS
PORT
> 1MΩ
PORT
PORT
PORT
R
1k
< 200Ω
LED
0.1μF
< 500kΩ
< 15kΩ
D1
LED
V
DD5
LTC4263-1
BAS19
D2
V
DD48
LED FLASH CODE
4263 F07
2 Flashes
5 Flashes
1 Flash
Off
Off
On
LED
. Diode D2
EXTERNAL COMPONENT SELECTION
This section discusses the other elements needed to make
a system including the LTC4263-1 function correctly. It is
recommended to adhere closely to the example application
circuits provided. For further assistance contact the Linear
Technology Applications department.
PoE System Power Delivery
The LTC4263-1 can output over 30W(typ) and is designed
to deliver 25W(min) to the PD over a 100 meter CAT5
cable for high power applications such as wireless access
points, security cameras and RFID readers. There are
several parameters external to the LTC4263-1 that limit
the power available to the PD. Figure 8 provides a simple
model used to calculate this power delivery.
The primary element affecting the delivery of power to the
PD is the supply feeding the LTC4263-1. By maximizing
this voltage, the highest and most effi cient power delivery
can be obtained. However, in order to adhere to common
safety requirements, the supply is normally limited to
60V and the IEEE 802.3af committee has chosen 57V as
a nominal maximum. In this example, a 56±1V power
supply output sets the lower limit to 55V. The LTC4263-1
overload current limit monitors port current and removes
FLASH PATTERN
LED Off
LED Off
LED On
LTC4263-1
15
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