Active Tower Thermal Solution

The power header on the baseboard must be positioned to allow the fan power cable to reach it. The power header identification and location should be documented in the platform documentation, or on the system board itself. Figure 10-5shows the location of the fan power connector relative to the processor socket. The baseboard power header should be positioned within 110 mm [4.33 inches] from the center of the processor socket.

Figure 10-4. Fan Power Cable Connector Description

Pin Signal

1GND

2+12 V

3SENSE

4CONTROL

Straight square pin, 4-pin terminal housing with polarizing ribs and friction locking ramp.

0.100" pitch, 0.025" square pin width.

Match with straight pin, friction lock header on mainboard.

1 2 3 4

Table 10-1. Fan Power and Signal Specifications

Description

Min

Typ

Max

Unit

Notes

 

 

 

 

 

 

+12V: 12 volt fan power supply

9.0

12.0

13.8

V

—

 

 

 

 

 

 

IC:

 

 

 

 

—

• Maximum fan steady-state current draw

—

1.2

—

A

 

• Maximum fan start-up current draw

—

3.0

—

A

 

 

 

 

 

 

 

SENSE: SENSE frequency

—

2

—

pulses per fan

1

 

 

 

 

revolution

 

 

 

 

 

 

 

CONTROL

21

25

28

kHz

2, 3

 

 

 

 

 

 

Notes:

 

 

 

 

 

1.Baseboard should pull this pin up to 5V with a resistor.

2.Open drain type, pulse width modulated.

3.Fan will have pull-up resistor for this signal to maximum of 5.25 V.

Figure 10-5. Baseboard Power Header Placement Relative to Processor Socket

 

R110

B

[4.33]

 

C

86

Thermal/Mechanical Specifications and Design Guidelines