PD671xxx - 8 / 12 / 24-Channel PoE AF and AT DIMM

Data Sheet (Non-confidential)

Copyright © 2009

Microsemi

Page 12

Rev. 1.0 / 17-March-10

Analog Mixed Signal Group

2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: (800) 713-4113, Outside the USA: (949) 221-7100 Fax: (949) 756-0308

Power Dissipation______________________________________

The PD671xxx power dissipation is concentrated within a few components distributed along the board as

follows. These power dissipation calculations are based on a 24 port DIMM supplied by a 48 VDC power

supply and located at ambient temperature of 70° C.

POWER DISSIP A TION [W]

COMPONENT

DESCRIPTION

UNITS

IEEE802.3 A F

0.35 A / POR T

IEEE802.3 A T

0.6 A / PORT

IEEE802.3 A T

0.65 A / POR T

Rs

Senses resistor

24

1.43

4.21

4.94

Mosfet

PoE switching Mosfet

24

0.56

1.64

1.93

PD69012

PoE manager

2

1.15

1.15

1.15

PD69000

PoE controller

1 *

0.02

0.02

0.02

Total

3.16

7.02

8.04

* Enhanced mode Master board only

Important

: When deploying an application utilizing the AC disconnect method, carefully select the diode type

and diode location on the mother board. The diode should be located away from the DIMM to prevent mutual

heating and the ventilation should be doubled to deal with higher power dissipation.

AC disconnect diodes power dissipation is based on 1 VDC forward voltage.

POWER DISSIP A TION [W]

COMPONENT

DESCRIPTION

UNITS

IEEE802.3 A F

0.35 A / POR T

IEEE802.3 A T

0.6 A / PORT

IEEE802.3 A T

0.65 A / POR T

Diode

AC disconnect diode

24

8.4

14.4

15.6

Physical Information ___________________________________

Figure 11 shows the PD671xxx DIMM mechanical outline, which can be used in printed circuit layout design.

PD671xxx DIMMs are designed to be mounted onto a 168-contact DIMM connector, capable of accepting

JEDEC MO-161 modules. All units are in millimeters.

Figure 11: DIMM Dimensions

Figure 12: Mechanical Outline of the PD671xxx DIMM