MC68HC705P9CDW FREESCALE [Freescale Semiconductor, Inc], MC68HC705P9CDW Datasheet - Page 140

• Manufacturer Part Number: MC68HC705P9CDW
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Electrical Specifications
12.5 Power Considerations
Technical Data
140
The average chip junction temperature, T
Where:
For most applications, P
Ignoring P
Solving equations (1) and (2) for K gives:
where K is a constant pertaining to the particular part. K can be
determined from equation (3) by measuring P
known T
by solving equations (1) and (2) iteratively for any value of T
Freescale Semiconductor, Inc.
T
P
P
P
JA
A
D
INT
I/O
For More Information On This Product,
= ambient temperature in C
= P
= package thermal resistance, junction to ambient in C/W
= power dissipation on input and output pins (user-determined)
A
= I
. Using this value of K, the values of P
INT
I/O
CC
Go to: www.freescale.com
K = P
, the relationship between P
+ P
Electrical Specifications
V
I/O
CC
D
x (T
T
= chip internal power dissipation
P
J
D
= T
A
I/O
=
+ 273 C) +
A
< P
T
+ (P
J
INT
+ 273 C
D
K
and can be neglected.
x
JA
JA
)
D
J
x (P
, in C can be obtained from:
and T
D
D
D
)
(at equilibrium) for a
2
and T
MC68HC705P9 — Rev. 4.0
J
is approximately:
J
can be obtained
A
MOTOROLA
.
(1)
(2)
(3)