MC9S12XDP512CFU
Model | MC9S12XDP512CFU |
Description | 16-BIT, FLASH, 40MHz, MICROCONTROLLER, PQFP80 |
PDF file | Total 1348 pages (File size: 8M) |
Chip Manufacturer | PHILIPS |
Appendix A Electrical Characteristics
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
J
) in
°C
can be
obtained from:
T
T
T
J
A
D
= Junction Temperature, [°C
]
= Ambient Temperature, [°C
]
= Total Chip Power Dissipation, [W]
= Package Thermal Resistance, [°C/W]
J
= T +
(
P
• Θ )
A
D
JA
P
Θ
JA
The total power dissipation can be calculated from:
P
P
INT
= Chip Internal Power Dissipation, [W]
D
= P
INT
+P
IO
Two cases with internal voltage regulator enabled and disabled must be considered:
1. Internal voltage regulator disabled
P
INT
= I
DD
⋅
V
DD
IO
+I
=
DDPLL
⋅
V
DDPLL
⋅
I
IO i
+I
DDA
⋅
V
DDA
P
∑
i
R
2
DSON
P
IO
is the sum of all output currents on I/O ports associated with V
DDX
and V
DDR
.
For R
DSON
is valid:
V
OL
= ----------- ;for outputs driven low
-
R
DSON
I
OL
respectively
R
V
–
V
DD5
OH
= ----------------------------------- ;for outputs driven high
-
DSON
I
OH
2. Internal voltage regulator enabled
P
INT
= I
DDR
⋅
V
DDR
+
I
DDA
⋅
V
DDA
I
DDR
is the current shown in Table A-10. and not the overall current flowing into V
DDR
, which
additionally contains the current flowing into the external loads with output high.
P
IO
=
∑
RDSON
⋅
IIOi2
i
P
IO
is the sum of all output currents on I/O ports associated with V
DDX
and V
DDR
.
MC9S12XDP512 Data Sheet, Rev. 2.21
1244
Freescale Semiconductor