Техническая Спецификация для Freescale Semiconductor Tower System Eval Kit for MC9S12GN32 TWR-S12GN32-KIT TWR-S12GN32-KIT
Модели
TWR-S12GN32-KIT
Electrical Characteristics
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor
1197
A.1.8
Power Dissipation and Thermal Characteristics
Power dissipation and thermal characteristics are closely related. The user must assure that the maximum
operating junction temperature is not exceeded. The average chip-junction temperature (T
operating junction temperature is not exceeded. The average chip-junction temperature (T
J
) in
°C can be
obtained from:
The total power dissipation can be calculated from:
P
IO
is the sum of all output currents on I/O ports associated with V
DDX
, whereby
T
J
T
A
P
D
Θ
JA
•
(
)
+
=
T
J
Junction Temperature, [
°C ]
=
T
A
Ambient Temperature, [
°C ]
=
P
D
Total Chip Power Dissipation, [W]
=
Θ
JA
Package Thermal Resistance, [
°C/W]
=
P
D
P
INT
P
IO
+
=
P
INT
Chip Internal Power Dissipation, [W]
=
P
IO
R
DSON
i
∑
I
IO
i
2
⋅
=
R
DSON
V
OL
I
OL
------------ for outputs driven low
;
=
R
DSON
V
DD35
V
OH
–
I
OH
--------------------------------------- for outputs driven high
;
=
P
INT
I
DDR
V
DDR
⋅
I
DDA
V
DDA
⋅
+
=