Intel L3426 BV80605004737AA Data Sheet

Product codes
BV80605004737AA
Page of 102
Boxed Processor Specifications
102
Dual-Core Intel® Xeon® Processor 3000 Series Datasheet
Notes:
1.
Set point variance is approximately ± 1 ° C from fan heatsink to fan heatsink.
If the boxed processor fan heatsink 4-pin connector is connected to a 4-pin 
motherboard header and the motherboard is designed with a fan speed controller with 
PWM output (CONTROL see 
) and remote thermal diode measurement 
capability the boxed processor will operate as follows:
As processor power has increased the required thermal solutions have generated 
increasingly more noise. Intel has added an option to the boxed processor that 
allows system integrators to have a quieter system in the most common usage.
The 4th wire PWM solution provides better control over chassis acoustics. This is 
achieved by more accurate measurement of processor die temperature through the 
processor's temperature diode (T-diode). Fan RPM is modulated through the use of 
an ASIC located on the motherboard that sends out a PWM control signal to the 4th 
pin of the connector labeled as CONTROL. The fan speed is based on actual 
processor temperature instead of internal ambient chassis temperatures.
If the new 4-pin active fan heat sink solution is connected to an older 3-pin 
baseboard processor fan header it will default back to a thermistor controlled 
mode, allowing compatibility with existing 3-pin baseboard designs. Under 
thermistor controlled mode, the fan RPM is automatically varied based on the Tinlet 
temperature measured by a thermistor located at the fan inlet.
For more details on specific motherboard requirements for 4-wire based fan speed 
control see the Dual-Core Intel
®
 Xeon
®
 Processor 3000 Series Thermal and Mechanical 
Design Guide.
§
Table 7-2.
Fan Heatsink Power and Signal Specifications
Boxed Processor Fan 
Heatsink Set Point (°C)
Boxed Processor Fan Speed
Notes
X ≤ 30
When the internal chassis temperature is below or equal to this set 
point, the fan operates at its lowest speed. Recommended maximum 
internal chassis temperature for nominal operating environment.
1
Y = 35
When the internal chassis temperature is at this point, the fan 
operates between its lowest and highest speeds. Recommended 
maximum internal chassis temperature for worst-case operating 
environment.
-
Z ≥ 38
When the internal chassis temperature is above or equal to this set 
point, the fan operates at its highest speed.
-