Intel E6700 Mechanical Design Guidelines - Page 107

Appendix F, Fan Performance for, Reference Design - specs

Page 107 highlights

Fan Performance for Reference Design Appendix F Fan Performance for Reference Design The fan power requirements for proper operation are listed in Table 7-3. Table 7-3. Fan Electrical Performance Requirements Requirement 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 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 In addition to comply with overall thermal requirements (Sections 5.1.1 and 6.2), and the general environmental reliability requirements (Sections 5.2 and 6.3) 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 Sections 5.2 and 6.3, 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. § Thermal and Mechanical Design Guidelines 107

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Fan Performance for Reference Design
Thermal and Mechanical Design Guidelines
107
Appendix F
Fan Performance for
Reference Design
The fan power requirements for proper operation are listed in Table 7–3.
Table 7–3. Fan Electrical Performance Requirements
Requirement
Value
Maximum Average fan current draw
1.5 A
Fan start-up current draw
2.2 A
Fan start-up current draw maximum
duration
1.0 second
Fan header voltage
12 V ± 5%
Tachometer output
2 pulse per revolution
Tachometer output signal
Open-collector (open-drain)
PWM signal input frequency
21 kHz to 28 kHz
PWM signal pull up in fan
3.3 V (recommended max)
5.25 V (absolute max)
PWM signal current source
Imax = 5 mA
(short circuit current)
PWM signal maximum voltage for logic
low
VIL = 0.8 V
PWM compliant function
RPM must be within spec for specified
duty cycle
In addition to comply with overall thermal requirements (Sections 5.1.1 and 6.2), and
the general environmental reliability requirements (Sections 5.2 and 6.3) 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 Sections 5.2
and 6.3, 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.
§