ELECTRICAL CHARACTERISTICS
MC68HC11F1
A-2
TECHNICAL DATA
NOTES:
1 This is an approximate value, neglecting PI/O.
2. For most applications PI/O PINT and can be neglected.
3. K is a constant pertaining to the device. Solve for K with a known TA and a measured PD (at equilibrium. Use
this value of K to solve for PD and TJ iteratively for any value of TA
Table A-2 Thermal Characteristics
Characteristic
Symbol
Value
Unit
Average Junction Temperature
TJ
TA + (PD x QJA)
°C
Ambient Temperature
TA
User-determined
°C
Package Thermal Resistance (Junction-to-Ambient)
68-Pin Plastic Leaded Chip Carrier
80-Pin Low Profile Quad Flat Pack (LQFP, 1.4 mm Thick)
QJA
50
80
°C/W
Total Power Dissipation
(Note 1)
PD
PINT + PI/O
K / (TJ + 273°C)
W
Device Internal Power Dissipation
PINT
IDD x VDD
W
I/O Pin Power Dissipation
(Note 2)
PI/O
User-determined
W
A Constant
(Note 3)
K
PD x (TA + 273°C) +
QJA x PD
2
W x
°C
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.