Electrical Specifications
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
266 Freescale Semiconductor
19.3 Functional Operating Range19.4 Thermal Characteristics
Characteristic Symbol Value Unit
Operating temperature range(1)
MC68HC908MR24CFU
MC68HC908MR24VFU
1. See Freescale representative for temperature availability.
C = Extended temperature range (–40°C to +85°C)
V = Automotive temperature range (–40°C to +105°C)
TA–40 to 85
–40 to 105
°C
Operating voltage range VDD 5.0 ± 10% V
Characteristic Symbol Value Unit
Thermal resistance,
64-pin QFP θJA 76 °C/W
I/O pin power dissipation PI/O User determined W
Power dissipation(1)
1. Power dissipation is a function of temperature.
PD
PD = (IDD x VDD) + PI/O =
K/(TJ + 273°C) W
Constant(2)
2. K is a 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.
KPD x (TA + 273°C)
+ PD2 x θJA
W/°C
Average junction temperature TJTA + (PD x θJA)°C
Maximum junction temperature TJM 125 °C