Intel Core 2 Extreme QX9300 BX80562QX9300 User Manual
Product codes
BX80562QX9300
Thermal Specifications and Design Considerations
68
Datasheet
5.
Processor TDP requirements in Intel Dynamic Acceleration mode are lesser than TDP in
HFM.
HFM.
6.
At Tj of 100
o
C
7.
At Tj of 50
o
C
8.
At Tj of 35
o
C
5.1
Monitoring Die Temperature
The processor incorporates three methods of monitoring die temperature:
• Thermal Diode
• Intel® Thermal Monitor
• Digital Thermal Sensor
• Intel® Thermal Monitor
• Digital Thermal Sensor
Note:
The Intel Thermal Monitor (detailed in
) must be used to determine when
the maximum specified processor junction temperature has been reached.
5.1.1
Thermal Diode
Intel’s processors utilize an SMBus thermal sensor to read back the voltage/current
characteristics of a substrate PNP transistor. Since these characteristics are a function
of temperature, in principle one can use these parameters to calculate silicon
temperature values. For older silicon process technologies (i.e., Intel® Core™2 Duo
mobile processors on 65nm process), it is possible to simplify the voltage/current and
temperature relationships by treating the substrate transistor as though it were a
simple diffusion diode. In this case, the assumption is that the beta of the transistor
does not impact the calculated temperature values. The resultant “diode” model
essentially predicts a quasi linear relationship between the base/emitter voltage
differential of the PNP transistor and the applied temperature (one of the
proportionality constants in this relationship is processor specific, and is known as the
diode ideality factor). Realization of this relationship is accomplished with the SMBus
thermal sensor that is connected to the transistor.
The quad-core processor, however, is built on Intel’s advanced 45-nm processor
technology. Due to this new highly advanced processor technology, it is no longer
possible to model the substrate transistor as a simple diode. To accurately calculate
silicon temperature one must use a full bi-polar junction transistor-type model. In this
model, the voltage/current and temperature characteristics include an additional
process dependant parameter which is known as the transistor “beta”. System
designers should be aware that the current thermal sensors on Santa Rosa platforms
may not be configured to account for “beta” and should work with their SMB thermal
sensor vendors to ensure they have a part capable of reading the thermal diode in BJT
model.
Offset between the thermal diode-based temperature reading and the Intel Thermal
Monitor reading may be characterized using the Intel Thermal Monitor’s automatic
mode activation of the thermal control circuit. This temperature offset must be taken
into account when using the processor thermal diode to implement power management
events. This offset is different than the diode Toffset value programmed into the
processor Model-Specific Register (MSR).
provide the diode interface and transistor model specifications.