Intel Celeron Processor on 0.13 Micron Process in the 478-Pin Package Datasheet

98 Intel
®
Celeron
®
Processor on 0.13 Micron Process in the 478-Pin Package Datasheet
Boxed Processor Specifications
8.4.2 Variable Speed Fan
The boxed processor fan will operate at different speeds over a short range of internal chassis
temperatures. This allows the processor fan to operate at a lower speed and noise level while
internal chassis temperatures are low. If internal chassis temperature increases beyond a lower set
point, the fan speed will rise linearly with the internal temperature until the higher set point is
reached. At that point, the fan speed is at its maximum. As fan speed increases, so does fan noise
levels. Systems should be designed to provide adequate air around the boxed processor fan
heatsink that remains below the lower set point. These set points, represented in Figure 45 and
Table 42, can vary by a few degrees from fan heatsink to fan heatsink. The internal chassis
temperature should be kept below 40 ºC. Meeting the processor’s temperature specification
(see Chapter 6) is the responsibility of the system integrator.
Note: The motherboard must supply a constant +12 V to the processor’s power header to ensure proper
operation of the variable speed fan for the boxed processor.
Figure 44. Boxed Processor Fan Heatsink Airspace Keep-Out Requirements
(Side 2 View)