X9000 Datasheet, PDF (74/77 Pages) Intel Corporation – Core2 Duo Processor and Core2 Extreme Processor on 45-nm Process

Thermal Specifications
Table 18.
5.1.2
Thermal Diode Parameters using Transistor Model
Symbol
Parameter
I_FW
I_E
n_Q
Beta
R_T
Forward Bias Current
Emitter Current
Transistor Ideality
Series Resistance
Min
5
5
0.997
0.1
3.0
Typ
—
—
1.001
0.4
4.5
Max
200
200
1.008
0.5
7.0
Unit
Notes
μA 1
μA 1
2, 3, 4
2, 3
Ω2
NOTES:
1.
Intel does not support or recommend operation of the thermal diode under reverse bias.
2.
Characterized across a temperature range of 50-105°C.
3.
Not 100% tested. Specified by design characterization.
4.
The ideality factor, nQ, represents the deviation from ideal transistor model behavior as
exemplified by the equation for the collector current:
I_C = I_S * (e ^qVBE^/nQ^kT –1)
where I_S = saturation current, q = electronic charge, V_BE = voltage across the transistor
base emitter junction (same nodes as VD), k = Boltzmann Constant, and T = absolute
temperature (Kelvin).
Intel® Thermal Monitor
The Intel Thermal Monitor helps control the processor temperature by activating the
TCC (thermal control circuit) when the processor silicon reaches its maximum operating
temperature. The temperature at which the Intel Thermal Monitor activates the TCC is
not user configurable. Bus traffic is snooped in the normal manner and interrupt
requests are latched (and serviced during the time that the clocks are on) while the
TCC is active.
With a properly designed and characterized thermal solution, it is anticipated that the
TCC would only be activated for very short periods of time when running the most
power-intensive applications. The processor performance impact due to these brief
periods of TCC activation is expected to be minor and hence not detectable. An under-
designed thermal solution that is not able to prevent excessive activation of the TCC in
the anticipated ambient environment may cause a noticeable performance loss and
may affect the long-term reliability of the processor. In addition, a thermal solution that
is significantly under-designed may not be capable of cooling the processor even when
the TCC is active continuously.
The Intel Thermal Monitor controls the processor temperature by modulating (starting
and stopping) the processor core clocks or by initiating an Enhanced Intel SpeedStep
Technology transition when the processor silicon reaches its maximum operating
temperature. The Intel Thermal Monitor uses two modes to activate the TCC: automatic
mode and on-demand mode. If both modes are activated, automatic mode takes
precedence.
There are two automatic modes called Intel Thermal Monitor 1 (TM1) and Intel Thermal
Monitor 2 (TM2). These modes are selected by writing values to the MSRs of the
processor. After automatic mode is enabled, the TCC will activate only when the
internal die temperature reaches the maximum allowed value for operation.
When TM1 is enabled and a high temperature situation exists, the clocks will be
modulated by alternately turning the clocks off and on at a 50% duty cycle. Cycle times
are processor speed-dependent and will decrease linearly as processor core frequencies
increase. Once the temperature has returned to a non-critical level, modulation ceases
and TCC goes inactive. A small amount of hysteresis has been included to prevent rapid
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