Electrical Specifications
Functional Operating Range
MC68HC908AB32 — Rev. 1.0 Technical Data
MOTOROLA Electrical Specifications 375
23.4 Functional Operating Range
23.5 Thermal Characteristics
Characteristic Symbol Value Unit
Operating temperature range
T
A
–40 to +85 –40 to +125 °C
Operating voltage range
V
DD
5.0 ±10% 5.0 ±10% V
Characteristic Symbol Value Unit
Thermal resistance
QFP (64-pin)
θ
JA
70 °C/W
I/O pin power dissipation
P
I/O
User-Determined W
Power dissipation
(1)
Notes:
1. Power dissipation is a function of temperature.
P
D
P
D
= (I
DD
× V
DD
) + P
I/O
=
K/(T
J
+ 273 °
C)
W
Constant
(2)
2. K is a constant unique to the device. K can be determined for a known T
A
and measured
P
D
. With this value of K, P
D
and T
J
can be determined for any value of T
A
.
K
P
D
× (T
A
+ 273 °
C
)
+ P
D
2
× θ
JA
W
/
°C
Average junction temperature
T
J
T
A
+ (P
D
× θ
JA
)
°C