Datasheet

Table Of Contents
MC68HC908GP20Rev 2.1 Advance Information
Freescale Semiconductor 379
23.4 Functional Operating Range
23.5 Thermal Characteristics
Characteristic Symbol Value Unit
Operating temperature range T
A
–40 to +85 °C
Operating voltage range V
DD
3.0 ±10%
5.0 ±10%
V
Characteristic Symbol Value Unit
Thermal resistance
PDIP (40-pin)
QFP (44-pin)
θ
JA
60
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
× 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
J
x (T
A
+ 273 °C)
+ P
D
2
× θ
JA
WC
Average junction temperature T
J
T
A
+ (P
D
× θ
JA
) °C
Maximum junction temperature T
JM
125 °C
Notes: