Thermal Specifications and Design Considerations
Table 29.
Thermal “Diode” Parameters using Transistor Model
Symbol
IFW
Parameter
Min
Typ
Max
Unit
Notes
Forward Bias Current
Emitter Current
5
—
—
200
200
µA
1, 2
IE
5
nQ
Transistor Ideality
0.997
0.391
2.79
1.001
—
1.005
0.760
6.24
-
3, 4, 5
3, 4
Beta
RT
Series Resistance
4.52
Ω
3, 6
NOTES:
1.
2.
3.
4.
5.
Intel does not support or recommend operation of the thermal diode under reverse bias.
Same as IFW in Table 28.
Preliminary data. Will be characterized across a temperature range of 50–80 °C.
Not 100% tested. Specified by design characterization.
The ideality factor, nQ, represents the deviation from ideal transistor model behavior as
exemplified by the equation for the collector current:
C = IS * (e qV /n kT –1)
BE
Q
I
Where IS = saturation current, q = electronic charge, VBE = voltage across the transistor
base emitter junction (same nodes as VD), k = Boltzmann Constant, and T = absolute
temperature (Kelvin).
The series resistance, RT, provided in the Diode Model Table (Table 28) can be used for
more accurate readings as needed.
6.
The Intel® Celeron® processor 400 Series does not support the diode correction offset
that exists on other Intel processors.
Table 30.
Thermal Diode Interface
Signal
Signal Name
Land Number
Description
THERMDA
THERMDC
AL1
AK1
diode anode
diode cathode
Datasheet
83
INTEL [ INTEL ]
