Fan Motor Performance; Table 4. Fan Electrical Performance Requirements - Intel QX9770 - Core 2 Extreme Quad-Core Processor Design Manual

5.1.5

Fan Motor Performance

The fan power requirements for proper operation are given Table 4.

Table 4. 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 (see Section 5.1.1), and the
general environmental reliability requirements (see Section 5.2) 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 50,000 hours.
• In addition to passing the environmental reliability tests described in Section 5.2,
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.
42
Requirement
LGA775 Socket Heatsink Loading
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