Fan Performance For Active Heatsink Thermal Solution; Table 7. Fan Electrical Performance Requirements - Intel Q9450 - Core 2 Quad Quad-Core Processor Design Manual

5.2.5

Fan Performance for Active Heatsink Thermal Solution

The fan power requirements for proper operation are given Table 7.

Table 7. Fan Electrical Performance Requirements

Maximum Average fan current draw
Fan start-up current draw
Fan start-up current draw maximum duration
Fan header voltage
Tachometer output
Tachometer output signal
PWM signal input frequency
PWM signal pull up in fan
PWM signal current source
PWM signal maximum voltage for logic low
PWM compliant function
In addition to comply with overall thermal requirements (Section 5.2.1), and the
general environmental reliability requirements (Section 5.3) the fan should meet the
following performance requirements:
 Mechanical wear out represents the highest risk reliability parameter for fans. The
capability of the functional mechanical elements (ball bearing, shaft, and tower
assembly) must be demonstrated to a minimum useful lifetime of 57,000 hours.
 In addition to passing the environmental reliability tests described in Section 5.3,
the fan must demonstrate adequate performance after 7,500 on/off cycles with
each cycle specified as 3 minutes on, 2 minutes off, at a temperature of 70 °C.
See the Fan Specification for 4-wire PWM Controlled Fans for additional details on the
fan specification.
48
Intel® Thermal/Mechanical Reference Design Information
Requirement Value
1.5 A
2.2 A
1.0 second
12 V ±5%
2 pulse per revolution
Open-collector (open-drain)
21 kHz to 28 kHz
3.3 V (recommended max)
5.25 V (absolute max)
Imax = 5 mA (short circuit current)
VIL = 0.8 V
RPM must be within spec for specified
duty cycle
Thermal and Mechanical Design Guidelines