MC68HC(7)08KH12Rev. 1.1 Advance Information
Freescale Semiconductor 249
17.4 Functional Operating Range17.5 Thermal Characteristics
Characteristic Symbol Value Unit
Operating Temperature Range TA0 to 85 °C
Operating Voltage Range VDD 4.0 to 5.5 V
Characteristic Symbol Value Unit
Thermal Resistance
QFP (64 Pins) θJA 70 °C/W
I/O Pin Power Dissipation PI/O User Determined W
Power Dissipation(1) PDPD = (IDD x VDD) + PI/O =
K/(TJ + 273 °C) W
Constant(2) KPD x (TA + 273 °C)
+ PD2 × θJA W/°C
Average Junction Temperature TJTA + (PD × θJA)°C
Maximum Junction Temperature TJM 100 °C
NOTES
1. Power dissipation is a function of temperature.
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.