mc9s08gt32a Freescale Semiconductor, Inc, mc9s08gt32a Datasheet - Page 260

• Manufacturer Part Number: mc9s08gt32a
• Description: Hcs08 Microcontrollers 8-bit Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Appendix A Electrical Characteristics
A.3
This section provides information about operating temperature range, power dissipation, and package
thermal resistance. Power dissipation on I/O pins is usually small compared to the power dissipation in
on-chip logic and voltage regulator circuits and it is user-determined rather than being controlled by the
MCU design. In order to take P
actual pin voltage and V
unusually high pin current (heavy loads), the difference between pin voltage and V
small.
The average chip-junction temperature (T
where:
For most applications, P
(if P
Solving equations 1 and 2 for K gives:
where K is a constant pertaining to the particular part. K can be determined from equation 3 by measuring
P
solving equations 1 and 2 iteratively for any value of T
260
D
(at equilibrium) for a known T
I/O
T
θ
P
P
P
JA
D
int
I/O
A
is neglected) is:
= Ambient temperature, °C
= P
1
2
= Package thermal resistance, junction-to-ambient, °C/W
= I
= Power dissipation on input and output pins — user determined
Operating temperature range (packaged)
Thermal resistance
Thermal Characteristics
Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance,
mounting site (board) temperature, ambient temperature, airflow, power dissipation of other components
on the board, and board thermal resistance.
Per SEMI G38-87 and JEDEC JESD51-2 with the single layer board horizontal. Single layer board is
designed per JEDEC JESD51-3.
64-pin LQFP (GBxxA)
48-pin QFN (GTxxA)
44-pin QFP (GTxxA)
int
DD
+ P
× V
I/O
DD
, Watts — chip internal power
I/O
SS
Rating
or V
<< P
K = P
I/O
DD
int
A
into account in power calculations, determine the difference between
and can be neglected. An approximate relationship between P
and multiply by the pin current for each I/O pin. Except in cases of
. Using this value of K, the values of P
Table A-2. Thermal Characteristics
MC9S08GB60A Data Sheet, Rev. 1.02
D
P
T
× (T
D
J
= K ÷ (T
= T
J
A
) in °C can be obtained from:
+ 273°C) + θ
A
+ (P
J
D
+ 273°C)
× θ
Symbol
θ
JA
T
A
JA
A
1,2
JA
.
)
× (P
D
)
2
–40 to 85
Value
118
65
82
D
and T
°C/W
Unit
J
SS
°C
can be obtained by
Freescale Semiconductor
or V
DD
Temp.
Code
—
C
will be very
D
Eqn. A-1
Eqn. A-2
Eqn. A-3
and T
J