mc68hc05x4dw Freescale Semiconductor, Inc, mc68hc05x4dw Datasheet - Page 127

• Manufacturer Part Number: mc68hc05x4dw
• Description: Xc68hc705x4 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

3-elec
where:
An approximate relationship between P
Solving equations [1] and [2] for K gives:
where K is a constant for a particular part. K can be determined by
measuring P
values of P
above equations. The package thermal characteristics are shown in
Table
Freescale Semiconductor, Inc.
P
P
INT
P
T
For More Information On This Product,
I/O
JA
D
1.
A
PA0–7, PB0–7
= Ambient temperature ( C)
= Package thermal resistance, junction-to-ambient ( C/W)
= P
= Internal chip power = I
= Power dissipation on input and output pins (user determined)
TX0, TX1
Pins
D
INT
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D
and T
Electrical Characteristics
(at equilibrium) for a known T
+ P
K
I/O
J
Figure 2. Equivalent test load
=
can be obtained for any value of T
3.26k
0.25k
(W)
R1
P D
T J
P D
2.38k
0.25k
=
T A
Thermal characteristics and power considerations
R2
T A
=
DD
+
---------------------- -
T J
273
+
• V
50pF
50pF
P D
+
C
K
DD
D
273
+
and T
(W)
JA P D
A
JA
. Using this value of K, the
J
point
(if P
Test
2
Electrical Characteristics
MC68HC05X4 Rev 1.0
I/O
A
is neglected) is:
C
by solving the
V
DD
= 4.5 V
R2
R1
[3
[2]
[1]
]