IEEE 802.3af PD Interface Controller

For Power-Over-Ethernet

12

______________________________________________________________________________________

60V

68nF

UVLO

GND

GATE

RCLASS

PGOOD

PGOOD

DC-DC CONVERTER

GND

-48V

WALL

ADAPTER

SUPPLY

D1

GND

V+

VREG

OUT

1

2

3

4

5

6

7

8

25.5k

Ω

SS_SHDN

MAX5014

MAX5940B

MAX5940D

LOAD

R4

4k

Ω

2W

D2

Typical Application Circuits (continued)

Figure 6. Adding Wall Adapter Input Supply (Wall Adapter Supply And Power-Over-Ethernet Co-Exist, the One with Higher Voltage

Provides Power To The Load)

Application Circuit 3

D2 prevents the wall adapter power from polluting the

discovery and classification signatures. The optional

R4 provides the 10mA minimum power maintenance

signature to keep the power-over-ethernet from discon-

necting.