Freescale Semiconductor MC68HC908MR32 manual Functional Operating Range, Thermal Characteristics

Electrical Specifications

19.3 Functional Operating Range

Characteristic	Symbol	Value	Unit
Operating temperature range(1)	TA	–40 to 85	°C
MC68HC908MR24CFU
MC68HC908MR24VFU		–40 to 105
Operating voltage range	VDD	5.0 ± 10%	V

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)

19.4 Thermal Characteristics

Characteristic	Symbol	Value		Unit
Thermal resistance,	θJA	76		°C/W
64-pin QFP
I/O pin power dissipation	PI/O	User determined		W
Power dissipation(1)	PD	PD = (IDD x VDD) + PI/O =		W
		K/(TJ + 273°C)
Constant(2)	K	PD x (TA + 273°C)		W/°C
		+ P	2 x θ
		D	JA
Average junction temperature	TJ	TA + (PD x θJA)		°C
Maximum junction temperature	TJM	125		°C

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.

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

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