mpc8544e Freescale Semiconductor, Inc, mpc8544e Datasheet - Page 104

• Manufacturer Part Number: mpc8544e
• Description: Mpc8544e Powerquicc Iii Integrated Processor
• Manufacturer: Freescale Semiconductor, Inc

Thermal
20.3.4
The MPC8544E has a temperature diode on the microprocessor that can be used in conjunction with other
system temperature monitoring devices (such as Analog Devices, ADT7461™). These devices use the
negative temperature coefficient of a diode operated at a constant current to determine the temperature of
the microprocessor and its environment. It is recommended that each device be individually calibrated.
The following are voltage forward biased range of the on-board temperature diode:
An approximate value of the ideality may be obtained by calibrating the device near the expected operating
temperature. The ideality factor is defined as the deviation from the ideal diode equation:
Another useful equation is:
104
V
V
f
f
> 0.40 V
< 0.90 V
Temperature Diode
V
I
fw
MPC8544E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 4
H
= I
– V
s
L
8
7
6
5
4
3
2
1
e
= n
nKT – 1
0
qV
KT
f
q
Preliminary—Subject to Change Without Notice
ln
0.5
Figure 64. Approach Air Velocity (m/s)
I
I
H
L
Freescale Confidential Proprietary
1
1.5
Thermalloy #2328B Pin-fin Heat Sink
2
(25 × 28 × 15 mm)
2.5
3
Freescale Semiconductor
3.5