Intel 2ND GENERATION CORE PROCESSOR FAMILY DESKTOP - THERMAL MECHANICAL S AND DESIGN GUIDELINES 01-2011, Технические характеристики

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Sensor Based Thermal Specification Design Guidance
68 Thermal/Mechanical Specifications and Design Guidelines
8.3.2 Thermal Design and Modelling
Based on the boundary conditions, the designer can now make the design selection of
the thermal solution components. The major components that can be mixed are the
fan, fin geometry, heat pipe or air cooled solid core design. There are cost and acoustic
trade-offs the customer can make.
To aide in the design process Intel provides TTV thermal models. Please consult your
Intel Field Sales Engineer for these tools.
8.3.3 Thermal Solution Validation
8.3.3.1 Test for Compliance to the TTV Thermal Profile
This step is the same as previously suggested for prior products. The thermal solution
is mounted on a test fixture with the TTV and tested at the following conditions:
• TTV is powered to the TDP condition
• Thermal solution fan operating at full speedMaximum airlflow through heatsink
• T
AMBIENT
at the boundary condition from Section 8.3.1
The following data is collected: TTV power, TTV T
CASE
and T
AMBIENT
. and used to
calculate 
CA
which is defined as:

CA
= (TTV T
CASE
- T
AMBIENT
) / Power
This testing is best conducted on a bench to eliminate as many variables as possible
when assessing the thermal solution performance. The boundary condition analysis as
described in
Section 8.3.1 should help in making the bench test simpler to perform.
8.3.3.2 Thermal Solution Characterization for Fan Speed Control
The final step in thermal solution validation is to establish the thermal solution
performance,

CA
and acoustics as a function of fan speed. This data is necessary to
allow the fan speed control algorithm developer to program the device. It also is
needed to asses the expected acoustic impact of the processor thermal solution in the
system.
The characterization data should be taken over the operating range of the fan. Using
the RCBF7-1156 (DHA-A) as the example the fan is operational from 900 to 3150 RPM.
The data was collected at several points and a curve was fit to the data, see
Figure 8-5 .
Taking data at 6 evenly distributed fan speeds over the operating range should provide
enough data to establish an equation. By using the equation from the curve fitting, a
complete set of required fan speeds as a function of

CA
can be developed. The results
from the reference thermal solution characterization are provided in Table 8-3 .
The fan speed control device may modulate the thermal solution fan speed (RPM) by
one of two methods. The first and preferred is pulse width modulation (PWM) signal
compliant to the 4-Wire Pulse Width Modulation (PWM) Controlled Fans specification.
The alternative is varying the input voltage to the fan. As a result the characterization
data needs to also correlate the RPM to PWM or voltage to the thermal solution fan. The
fan speed algorithm developer needs to associate the output command from the fan
speed control device with the required thermal solution performance as stated in
Table 8-3 . Regardless of which control method is used, the term RPM will be used to
indicate required fan speed in the rest of this document.