Datasheet

Appendix A Electrical Characteristics and Timing Specifications
MC9S08AC16 Series Data Sheet, Rev. 9
294 Freescale Semiconductor
maximum-rated voltages to this high-impedance circuit. Reliability of operation is enhanced if unused
inputs are tied to an appropriate logic voltage level (for instance, either V
SS
or V
DD
).
A.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 it is user-determined rather than being controlled by the MCU design. In order to take
P
I/O
into account in power calculations, determine the difference between actual pin voltage and V
SS
or
Table A-2. Absolute Maximum Ratings
Rating Symbol Value Unit
Supply voltage V
DD
–0.3 to + 5.8 V
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, then use the larger 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 external power supply going
out of regulation. Ensure external V
DD
load will shunt current greater than maximum injection
current. This will be the greatest risk when the MCU is not consuming power. Examples are: if
no system clock is present, or if the clock rate is very low which would reduce overall power
consumption.
I
D
 25 mA
Maximum current into V
DD
I
DD
120 mA
Storage temperature T
stg
–55 to +150 C
Maximum junction temperature T
J
150 C