Datasheet

Electrical Specifications
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
184 Freescale Semiconductor
17.3 Functional Operating Range
17.4 Thermal Characteristics
Characteristic Symbol Value Unit
Operating temperature range
T
A
–40 to 125 °C
Operating voltage range
V
DD
3.0 ± 10%
5.0 ± 10%
V
Characteristic Symbol Value Unit
Thermal resistance
PDIP (16 pins)
SOIC (16 pins)
θ
JA
66
95
°C/W
I/O pin power dissipation
P
I/O
User determined W
Power dissipation
(1)
1. Power dissipation is a function of temperature.
P
D
P
D
= (I
DD
x 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
x (T
A
+ 273°C)
+ P
D
2
x θ
JA
W/°C
Average junction temperature
T
J
T
A
+ (P
D
x θ
JA
)
°C
Maximum junction temperature
T
JM
135 °C