Electrical Specifications
22.3 Functional Operating Range
Table 22-2. Operating Range
Characteristic
Operating temperature range
Operating voltage range
Symbol
Value
Unit
°C
TA
–40 to +85
2.7 to 5.5
VDD
V
22.4 Thermal Characteristics
Table 22-3. Thermal Characteristics
Characteristic
Symbol
Value
Unit
Thermal resistance
42-Pin SDIP
44-Pin QFP
48-Pin LQFP
60
95
80
°C/W
°C/W
°C/W
θJA
PI/O
PD
I/O pin power dissipation
Power dissipation(1)
User determined
W
PD = (IDD × VDD) + PI/O
K/(TJ + 273 °C)
=
W
PD x (TA + 273 °C)
+ PD2 × θJA
Constant(2)
K
W/°C
TJ
TA + (PD × θJA)
Average junction temperature
Maximum junction temperature
°C
°C
TJM
100
1. Power dissipation is a function of temperature.
2. K constant unique to the device. K can be determined for a known TA and measured PD.
With this value of K, PD and TJ can be determined for any value of TA.
MC68HC908AP Family Data Sheet, Rev. 4
298
Freescale Semiconductor
FREESCALE [ Freescale ]
