Intel 4 620 JM80547PG0722MM Data Sheet
Product codes
JM80547PG0722MM
Datasheet
83
Thermal Specifications and Design Considerations
5.2.5
THERMTRIP# Signal
Regardless of whether or not the Thermal Monitor feature is enabled, in the event of a catastrophic
cooling failure, the processor will automatically shut down when the silicon has reached an
elevated temperature (refer to the THERMTRIP# definition in
cooling failure, the processor will automatically shut down when the silicon has reached an
elevated temperature (refer to the THERMTRIP# definition in
). At this point, the FSB
signal THERMTRIP# will go active and stay active as described in
. THERMTRIP#
activation is independent on processor activity and does not generate any bus cycles.
5.2.6
T
CONTROL
and Fan Speed Reduction
T
CONTROL
is a temperature specification based on a temperature reading from the thermal diode.
The value for T
CONTROL
will be calibrated in manufacturing and configured for each processor.
When T
DIODE
is above T
CONTROL
, T
C
must be at or below T
C
(max) as defined by the thermal
profile in
and
; otherwise, the processor temperature can be maintained at
T
CONTROL
(or lower) as measured by the thermal diode.
The purpose of this feature is to support acoustic optimization through fan speed control. Contact
your Intel representative for further details and documentation.
your Intel representative for further details and documentation.
5.2.7
Thermal Diode
The processor incorporates an on-die thermal diode. A thermal sensor located on the system board
may monitor the die temperature of the processor for thermal management/long term die
temperature change purposes.
may monitor the die temperature of the processor for thermal management/long term die
temperature change purposes.
provide the diode parameter and interface
specifications. This thermal diode is separate from the Thermal Monitor’s thermal sensor and
cannot be used to predict the behavior of the Thermal Monitor.
cannot be used to predict the behavior of the Thermal Monitor.
Table 5-5. Thermal Diode Parameters
Symbol
Parameter
Min
Typ
Max
Unit
Notes
I
FW
Forward Bias Current
11
—
187
µA
1
NOTES:
1.
Intel does not support or recommend operation of the thermal diode under reverse bias.
n
Diode Ideality Factor
1.0083
1.011
1.023
2, 3, 4, 5
2.
Characterized at 75 °C.
3.
Not 100% tested. Specified by design characterization.
4.
The ideality factor, n, represents the deviation from ideal diode behavior as exemplified by the diode equation:
I
FW
= I
S
* (e
qV
D
/nkT
–1)
where I
S
= saturation current, q = electronic charge, V
D
= voltage across the diode, k = Boltzmann Constant,
and T = absolute temperature (Kelvin).
5.
Devices found to have an ideality factor of 1.0183 to 1.023 will create a temperature error approximately 2 °C higher than
the actual temperature. To minimize any potential acoustic impact of this temperature error, T
the actual temperature. To minimize any potential acoustic impact of this temperature error, T
CONTROL
will be increased by
2 °C on these parts.
R
T
Series Resistance
3.242
3.33
3.594
Ω
2, 3, 6
6.
The series resistance, R
T
, is provided to allow for a more accurate measurement of the thermal diode temperature. R
T
, as
defined, includes the pins of the processor but does not include any socket resistance or board trace resistance between
the socket and the external remote diode thermal sensor. R
the socket and the external remote diode thermal sensor. R
T
can be used by remote diode thermal sensors with automatic
series resistance cancellation to calibrate out this error term. Another application is that a temperature offset can be manually
calculated and programmed into an offset register in the remote diode thermal sensors as exemplified by the equation:
calculated and programmed into an offset register in the remote diode thermal sensors as exemplified by the equation:
T
error
= [R
T
* (N–1) * I
FWmin
] / [nk/q * ln N]
where T
error
= sensor temperature error, N = sensor current ratio, k = Boltzmann Constant, q = electronic
charge.