Freescale Semiconductor, Inc.
Table A-2 Thermal Characteristics
Characteristic
Symbol
Value
T + (P x Q )
JA
Unit
°C
Average Junction Temperature
Ambient Temperature
T
J
A
D
T
User-determined
°C
A
Package Thermal Resistance (Junction-to-Ambient)
68-Pin Plastic Leaded Chip Carrier
80-Pin Low Profile Quad Flat Pack (LQFP, 1.4 mm Thick)
Q
JA
50
80
°C/W
°C/W
Total Power Dissipation
(Note 1)
P
P
+ P
I/O
W
D
INT
K / (T + 273°C)
J
Device Internal Power Dissipation
I/O Pin Power Dissipation
A Constant
P
I
x V
DD
W
W
INT
DD
(Note 2)
(Note 3)
P
User-determined
I/O
K
P
x (T + 273°C) +
Q
W x °C
D
A
2
x P
D
JA
NOTES:
1 This is an approximate value, neglecting P
.
I/O
2. For most applications P « P
and can be neglected.
I/O
INT
3. K is a constant pertaining to the device. Solve for K with a known T and a measured P (at equilibrium. Use
A
D
this value of K to solve for P and T iteratively for any value of T
D
J
A
ELECTRICAL CHARACTERISTICS
MC68HC11F1
TECHNICAL DATA
A-2
For More Information On This Product,
Go to: www.freescale.com
FREESCALE [ Freescale ]
