mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 1244

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Appendix A Electrical Characteristics
A.1.8
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
obtained from:
T
T
P
The total power dissipation can be calculated from:
P
Two cases with internal voltage regulator enabled and disabled must be considered:
1244
J
A
D
INT
JA
=
=
1. Internal voltage regulator disabled
2. Internal voltage regulator enabled
=
=
Junction Temperature, [ C
Ambient Temperature, [ C
=
Total Chip Power Dissipation, [W]
Package Thermal Resistance, [ C/W]
P
For R
respectively
I
additionally contains the current flowing into the external loads with output high.
P
Chip Internal Power Dissipation, [W]
DDR
IO
IO
is the sum of all output currents on I/O ports associated with V
is the sum of all output currents on I/O ports associated with V
Power Dissipation and Thermal Characteristics
is the current shown in Table A-10. and not the overall current flowing into V
DSON
is valid:
P
INT
R
DSON
=
I
P
R
DD
INT
MC9S12XDP512 Data Sheet, Rev. 2.17
DSON
=
V
P
P
=
DD
V
----------------------------------- - for outputs driven high
IO
IO
T
I
DD5
J
DDR
=
P
+
=
=
=
D
I
V
----------- - for outputs driven low
I
I
OH
DDPLL
OL
OL
T
–
=
i
i
A
V
V
P
;
OH
+
R
R
DDR
INT
DSON
DSON
P
;
D
V
+
+
DDPLL
P
I
DDA
IO
JA
I
I
IO i
IO i
2
2
+
V
DDA
I
DDA
V
DDX
DDX
DDA
and V
and V
Freescale Semiconductor
DDR
DDR
.
.
J
DDR
) in C can be
, which