Datasheet

Dual-Core Intel® Xeon® Processor 5000 Series Datasheet 81
Thermal Specifications
.
Notes:
1. Intel does not support or recommend operation of the thermal diode under reverse bias.
2. Same as I
FW
in the diode model in Table 6-9.
3. Characterized across a temperature range of 50-80°C.
4. Not 100% tested. Specified by design characterization.
5. The ideality factor, n
Q
, represents the deviation from ideal transistor model behavior as exemplified by the
equation for the collector current: I
C
= I
S
* (e
qVBE/n
Q
kT
- 1)
Where I
S
= saturation current, q = electronic charge, V
BE
= voltage across the transistor based emitter
junction (same nodes as V
D
), k = Boltzmann Constant, and T = absolute temperature (Kelvin).
6. The series resistance, R
T
provided in Table 6-9 can be used for more accurate readings as needed.
Notes:
1. See the Dual-Core Intel
®
Xeon
®
Processor 5000 Series Thermal/Mechanical Design Guidelines for more
information on how to use the Tdiode_Offset, Tdiode_Base and n
trim
parameters for fan speed control.
§
Table 6-10. Thermal Diode Interface
Land Name Land Number Description
THERMDA AL1 diode anode
THERMDC AK1 diode cathode
THERMDA2 AJ7 diode anode
THERMDC2 AH7 diode cathode
Table 6-11. Thermal Diode Parameters using Transistor Model
Symbol Parameter Min Typ Max Unit Notes
I
FW
Forward Bias Current 5 - 200 µA 1, 2
I
E
Emitter Current 5 - 200 µA
n
Q
Transistor Ideality 0.997 1.001 1.005 - 3, 4, 5
Beta - 0.391 - 0.760 - 3, 4
R
T
Series Resistance 2.79 4.52 6.24
Ω
3, 6
Table 6-12. Parameters for Tdiode Correction Factor
Symbol Parameter Typ Unit Notes
n
trim
Diode Ideality used to calculate
Tdiode_Offset
1.008 1
Tdiode_Base 0 °C 1