STR710F STMICROELECTRONICS [STMicroelectronics], STR710F Datasheet - Page 46

• Manufacturer Part Number: STR710F
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

STR71xF - PACKAGE CHARACTERISTICS
3.2 Thermal Characteristics
The average chip-junction temperature, T
following equation:
T
Where:
Most of the time for the applications P
P
or memories.
An approximate relationship between P
P
Therefore (solving equations 1 and 2):
K = P
where:
Table 24. Thermal characteristics
46/49
J
I/O
D
Symbol
– T
– Θ
– P
– P
– P
– K is a constant for the particular part, which may be determined from equation (3) by meas-
= T
Θ
Θ
Θ
Θ
= K / (T
uring P
be obtained by solving equations (1) and (2) iteratively for any value of T
may be significant if the device is configured to drive continuously external modules and/
JA
JA
JA
JA
A
D
INT
I/O
JA
D
A
is the Ambient Temperature in °C,
is the sum of P
x (T
+ (P
is the Package Junction-to-Ambient Thermal Resistance, in °C/W,
represents the Power Dissipation on Input and Output Pins;
is the product of I
Thermal Resistance Junction-Ambient
TQFP 144 - 20 x 20 mm / 0.5 mm pitch
Thermal Resistance Junction-Ambient
TQFP 64 - 10 x 10 mm / 0.5 mm pitch
Thermal Resistance Junction-Ambient
LFBGA 64 - 8 x 8 x 1.7mm
Thermal Resistance Junction-Ambient
LFBGA 144 - 10 x 10 x 1.7mm
J
D
A
D
+ 273°C)
(at equilibrium) for a known T
+ 273°C) + Θ
x Θ
JA
)
INT
and P
DD
JA
x P
and V
I/O
D
Parameter
2
(P
DD
D
, expressed in Watts. This is the Chip Internal Power.
I/O
= P
D
< P
and T
A.
J
INT
, in degrees Celsius, may be calculated using the
INT
Using this value of K, the values of P
+ P
J
and may be neglected. On the other hand,
(if P
I/O
),
I/O
is neglected) is given by:
(1)
(2)
(3)
Value
TBD
TBD
42
45
A
.
D
and T
°C/W
°C/W
°C/W
°C/W
Unit
J
may