MC68HC705JD FREESCALE [Freescale Semiconductor, Inc], MC68HC705JD Datasheet - Page 68

• Manufacturer Part Number: MC68HC705JD
• Description: member of the low-cost
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

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11.3 Power Considerations
11-2
The average chip-junction temperature, T
where:
For most applications P
The following is an approximate relationship between 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
K, the values of P
iteratively for any value of T
T
P
P
P
JA
A
D
INT
I/O
= Ambient temperature, C
= P
= Package thermal resistance, junction to ambient, C/W
= Power dissipation on input and output pins (user-determined)
= I
INT
DD
+ P
V
I/O
DD
Freescale Semiconductor, Inc.
D
For More Information On This Product,
watts (chip internal power)
and T
K = P
ELECTRICAL SPECIFICATIONS
I/O
J
Go to: www.freescale.com
<< P
can be obtained by solving equations (1) and (2)
A
D
D
.
P
(at equilibrium) for a known T
T
D
INT
(T
J
= K
= T
A
and can be neglected.
+ 273 C) +
A
+ (P
(T
J
J
+ 273 C)
, in C, can be obtained from:
D
JA
JA
)
(P
D
D
and T
)
2
A
. Using this value of
J
(neglecting P
Rev. 2
I/O
(1)
(2)
(3)
):