DP83848C-POE-EK National Semiconductor, DP83848C-POE-EK Datasheet - Page 33

• Manufacturer Part Number: DP83848C-POE-EK
• Description: BOARD EVALUATION DP83848C
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of DP83848C-POE-EK

• Main Purpose: Special Purpose DC/DC, Power Over Ethernet
• Outputs And Type: 1, Isolated
• Power - Output: 24W
• Voltage - Output: 3.3V
• Current - Output: 7.3A
• Voltage - Input: 39 ~ 57V
• Regulator Topology: Flyback
• Frequency - Switching: 250kHz
• Board Type: Fully Populated
• Utilized Ic / Part: LM5072
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

5.0 Design Guidelines
5.1 TPI Network Circuit
Figure 11 shows the recommended circuit for a 10/100
Mb/s twisted pair interface. To the right is a partial list of
recommended transformers. It is important that the user
realize that variations with PCB and component character-
istics requires that the application be tested to ensure that
the circuit meets the requirements of the intended applica-
tion.
PLACE RESISTORS AND
CAPACITORS CLOSE TO
THE DEVICE.
RD+
RD-
TD-
TD+
49.9
49.9
49.9
49.9
Figure 11. 10/100 Mb/s Twisted Pair Interface
Vdd
Vdd
0.1 F
0.1 F
33
All values are typical and are +/- 1%
Pulse H1102
Pulse H2019
Pulse J0011D21
Pulse J0011D21B
Vdd
NOTE: CENTER TAP IS PULLED TO VDD
*PLACE CAPACITORS CLOSE TO THE
0.1µF*
0.1µF*
TRANSFORMER CENTER TAPS
COMMON MODE CHOKES
MAY BE REQUIRED.
1:1
1:1
T1
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RD-
RD+
TD-
TD+
RJ45