Datasheet

Appendix A Electrical Characteristics
MC9S08SG8 MCU Series Data Sheet, Rev. 8
Freescale Semiconductor 285
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 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.
Table A-3. Thermal Characteristics
Num C Rating Symbol Value Unit
Temp Rated
1
1
Electrical characteristics only apply to the temperature rated devices marked with x.
Standar
d
AEC
Grade 0
1 — Operating temperature range
(packaged)
T
L
to T
H
C
C
T
A
–40 to 85 x
V–40 to 105x
M–40 to 125x
W–40 to 150 x
2 D Maximum junction temperature C
CT
J
95 x
V115x
M135x
W155 x
D Thermal resistance
2,3
Single-layer board
2
Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance, mounting site (board) temperature,
ambient temperature, air flow, power dissipation of other components on the board, and board thermal resistance.
3
Junction to Ambient Natural Convection

JA
Airflow at
200 ft/min
Natural
Convection
3 8-pin NB SOIC 131 153
C/W
x
16-pin TSSOP 115 135 x x
20-pin TSSOP 95 115 x
4 D Thermal resistance
2,3
Four-layer board

JA
Airflow at
200 ft/min
Natural
Convection
8-pin NB SOIC 95 102
C/W
x
16-pin TSSOP 86 94 x x
20-pin TSSOP 69 76 x