Datasheet

Electrical Characteristics
MC9S08LG32 Series Data Sheet, Rev. 9
Freescale Semiconductor 11
2.4 Thermal Characteristics
This section provides information about operating temperature range, power dissipation, and package thermal resistance. Power
dissipation on I/O pins is usually small compared to the power dissipation in On-Chip logic and voltage regulator circuits, and
it is user-determined rather than being controlled by the MCU design. To take P
I/O
into account in power calculations, determine
the difference between actual pin voltage and V
SS
or V
DD
and multiply by the pin current for each I/O pin. Except in cases of
unusually high pin current (heavy loads), the difference between pin voltage and V
SS
or V
DD
will be very small.
The average chip-junction temperature (T
J
) in C can be obtained from:
T
J
= T
A
+ (P
D
 
JA
) Eqn. 1
Table 4. Absolute Maximum Ratings
Rating Symbol Value Unit
Supply voltage V
DD
–0.3 to +5.8 V
Maximum current into V
DD
I
DD
120 mA
Digital input voltage V
In
–0.3 to V
DD
+0.3 V
Instantaneous maximum current
Single pin limit (applies to all port pins)
1, 2, 3
1
Input must be current limited to the value specified. To determine the value of the required
current-limiting resistor, calculate resistance values for positive (V
DD
) and negative (V
SS
) clamp
voltages and use the largest of the two resistance values.
2
All functional non-supply pins are internally clamped to V
SS
and V
DD
.
3
Power supply must maintain regulation within operating V
DD
range during instantaneous and
operating maximum current conditions. If positive injection current (V
In
> V
DD
) is greater than
I
DD
, the injection current may flow out of V
DD
and could result in an external power supply going
out of regulation. Ensure that the external V
DD
load will shunt current greater than maximum
injection current, this will be of greater risk when the MCU is not consuming power. For instance,
if no system clock is present, or if the clock rate is very low (which would reduce overall power
consumption).
I
D
25
2
mA
Storage temperature range T
stg
–55 to 150 C
Table 5. Thermal Characteristics
Rating Symbol Value Unit
Operating temperature range
(packaged)
T
A
T
L
to T
H
–40 to +105
C
Maximum junction temperature T
J
125 C
Thermal resistance
Single-layer board
80-pin LQFP
64-pin LQFP
48-pin LQFP

JA
61
71
80
C/W
Thermal resistance
Four-layer board
80-pin LQFP
64-pin LQFP
48-pin LQFP

JA
48
52
56
C/W