6
MAC7100 Microcontroller Family Hardware Specifications
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA
Electrical Characteristics
3.4.1
5 V I/O Pins
The I/O pins operate at a nominal level of 5 V. This class of pins is comprised of the clocks, control and general
purpose/peripheral pins. The internal structure of these pins is identical; however, some functionality may be
disabled (for example, for analog inputs the output drivers, pull-up/down resistors are permanently disabled).
3.4.2
Oscillator Pins
The pins XFC, EXTAL, XTAL are dedicated to the oscillator and operate at a nominal level of 2.5 V.
3.5
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.
Note that the JEDEC specification reserves the symbol R
θ
JA
or
θ
JA
(Theta-JA) strictly for junction-to-
ambient thermal resistance on a 1s test board in natural convection environment. R
θ
JMA
or
θ
JMA
(Theta-JMA) will be used for both junction-to-ambient on a 2s2p test board in natural convection and for
junction-to-ambient with forced convection on both 1s and 2s2p test boards. It is anticipated that the generic
name,
θ
JA
, will continue to be commonly used.
The average chip-junction temperature (T
J
) in
°
C is obtained from:
The total power dissipation is calculated from:
Two cases for P
IO
, with the internal voltage regulator enabled and disabled, must be considered:
1. Internal Voltage Regulator disabled:
P
IO
is the sum of all output currents on I/O ports associated with V
DD
X and V
DD
R.
V
I
OL
or
2. Internal voltage regulator enabled:
I
DD
R is the current shown in Table 12 and not the overall current flowing into V
DD
R, which
additionally contains the current flowing into the external loads with output high.
T
J
T
A
Θ
JA
(
)
+
=
T
J
T
A
P
D
Θ
JA
Junction Temperature (
°
C)
=
Ambient Temperature (
°
C)
=
Total Chip Power Dissipation (W)
=
Package Thermal Resistance (
°
C/W)
=
P
D
P
INT
P
IO
+
=
P
INT
P
INT
Chip Internal Power Dissipation (W)
=
I
DD
V
DD
×
(
)
I
DD
PLL
V
DD
PLL
×
(
)
I
DD
A
V
DD
A
×
(
)
+
+
=
P
IO
R
DSON
i
∑
I
IO
i
(
)
2
=
R
DSON
---------
(for outputs driven low)
=
R
DSON
V
5
-------------------------------
(for outputs driven high)
V
–
I
OL
=
P
INT
I
DD
R
V
DD
R
×
(
)
I
DD
A
V
DD
A
×
(
)
+
=
F
Freescale Semiconductor, Inc.
n
.