Datasheet

Electrical Specifications
MC68HC908LJ12 — Rev. 2.1 Technical Data
Freescale Semiconductor Electrical Specifications 393
23.4 Functional Operating Range
23.5 Thermal Characteristics
Table 23-2. Operating Range
Characteristic Symbol Value Unit
Operating temperature range
T
A
– 40 to +85 °C
Operating voltage range
V
DD
3.3V ± 10%
5.0V ± 10%
V
Table 23-3. Thermal Characteristics
Characteristic Symbol Value Unit
Thermal resistance
52-pin LQFP
64-pin LQFP
64-pin QFP
θ
JA
85
80
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 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
x (T
A
+ 273 °C)
+ P
D
2
× θ
JA
W/°C
Average junction temperature
T
J
T
A
+ (P
D
× θ
JA
)
°C