Datasheet

STM8S207xx, STM8S208xx Package characteristics
Doc ID 14733 Rev 12 95/103
11.2 Thermal characteristics
The maximum chip junction temperature (T
Jmax
) must never exceed the values given in
Tabl e 18: General operating conditions on page 55.
The maximum chip-junction temperature, T
Jmax
, in degrees Celsius, may be calculated
using the following equation:
T
Jmax
= T
Amax
+ (P
Dmax
x Θ
JA
)
Where:
● T
Amax
is the maximum ambient temperature in ° C
● Θ
JA
is the package junction-to-ambient thermal resistance in ° C/W
● P
Dmax
is the sum of P
INTmax
and P
I/Omax
(P
Dmax
= P
INTmax
+ P
I/Omax
)
● P
INTmax
is the product of I
DD
and V
DD
, expressed in Watts. This is the maximum chip
internal power.
● P
I/Omax
represents the maximum power dissipation on output pins, where:
P
I/Omax
= Σ (V
OL
*I
OL
) + Σ((V
DD
-V
OH)
*I
OH
), and taking account of the actual V
OL
/I
OL
and
V
OH
/I
OH
of the I/Os at low and high level in the application.
11.2.1 Reference document
JESD51-2 integrated circuits thermal test method environment conditions - natural
convection (still air). Available from www.jedec.org.
Table 57. Thermal characteristics
(1)
1. Thermal resistances are based on JEDEC JESD51-2 with 4-layer PCB in a natural convection
environment.
Symbol Parameter Value Unit
Θ
JA
Thermal resistance junction-ambient
LQFP 80 - 14 x 14 mm
38 °C/W
Θ
JA
Thermal resistance junction-ambient
LQFP 64 - 14 x 14 mm
45 °C/W
Θ
JA
Thermal resistance junction-ambient
LQFP 64 - 10 x 10 mm
46 °C/W
Θ
JA
Thermal resistance junction-ambient
LQFP 48 - 7 x 7 mm
57 °C/W
Θ
JA
Thermal resistance junction-ambient
LQFP 44 - 10 x 10 mm
54 °C/W
Θ
JA
Thermal resistance junction-ambient
LQFP 32 - 7 x 7 mm
60 °C/W