Intel E2140 BX80557E2140 Data Sheet

Datasheet

101

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 

CPU 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 appropriate Thermal and Mechanical Design Guidelines (see 

º

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

1. Set point variance is approximately ± 1 °C from fan heatsink to fan heatsink.

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.

-