4 functional operating range, 5 thermal characteristics, Functional operating range – Freescale Semiconductor MC68HC08KH12 User Manual

Page 249: Thermal characteristics

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MC68HC(7)08KH12

Rev. 1.1

Advance Information

Freescale Semiconductor

249

17.4 Functional Operating Range

17.5 Thermal Characteristics

Characteristic

Symbol

Value

Unit

Operating Temperature Range

T

A

0 to 85

°

C

Operating Voltage Range

V

DD

4.0 to 5.5

V

Characteristic

Symbol

Value

Unit

Thermal Resistance

QFP (64 Pins)

θ

JA

70

°C/W

I/O Pin Power Dissipation

P

I/O

User Determined

W

Power Dissipation

(1)

P

D

P

D

= (I

DD

x V

DD

) + P

I/O

=

K/(T

J

+ 273

°C)

W

Constant

(2)

K

P

D

x

(T

A

+ 273

°C

)

+ P

D

2

×

θ

JA

W/

°C

Average Junction Temperature

T

J

T

A

+ (P

D

× θ

JA

)

°C

Maximum Junction Temperature

T

JM

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 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

.

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