mpc8640 Freescale Semiconductor, Inc, mpc8640 Datasheet - Page 114

• Manufacturer Part Number: mpc8640
• Description: Integrated Host Processor
• Manufacturer: Freescale Semiconductor, Inc

Thermal
The thermal model uses approximate dimensions to reduce grid. Please refer to the case outline for actual
dimensions.
19.2.4
The MPC8640 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. For proper operation, the monitoring device used should
auto-calibrate the device by canceling out the V
The following are the specifications of the MPC8640 on-board temperature diode:
114
V
V
Operating range 2–300 μA
Diode leakage < 10 nA at 125 °C
Ideality factor over 5–150 μA at 60 °C: n = 1.0275
f
f
> 0.40 V
< 0.90 V
Temperature Diode
Conductivity
MPC8640 and MPC8640D Integrated Host Processor Hardware Specifications, Rev. 3
Bump and Underfill (12.4 × 15.3 × 0.07 mm)
Silicon
k
k
k
k
k
k
k
z
x
y
z
x
y
z
C5 Solder layer (33 × 33 × 0.4 mm)
Substrate (33 × 33 × 1.2 mm)
Die (12.4 × 15.3 × 0.86 mm)
Collapsed Resistance
Figure 62. Recommended Thermal Model of MPC8640
Temperature
dependent
Value
0.034
0.034
13.5
13.5
5.3
5.3
9.6
BE
W/(m • K)
W/(m • K)
W/(m • K)
variation of each MPC8640’s internal diode.
Unit
±
0.9%
y
z
Side View of Model (Not to Scale)
Top View of Model (Not to Scale)
x
Bump and Underfill
C5 solder layer
Substrate
Substrate
Die
Die
Freescale Semiconductor