Datasheet

Electrical parameters STM8L151x2, STM8L151x3
96/112 Doc ID 018780 Rev 4
7.4 Thermal characteristics
The maximum chip junction temperature (T
Jmax
) must never exceed the values given in
Table 14: General operating conditions on page 52.
The maximum chip-junction temperature, T
Jmax
, in degree 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
),
taking into account the actual V
OL
/I
OL
and V
OH
/I
OH
of the I/Os at low and high level in
the application.
Table 54. 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 48- 7 x 7 mm
65 °C/W
Θ
JA
Thermal resistance junction-ambient
UFQFPN 32 - 5 x 5 mm
38 °C/W
Θ
JA
Thermal resistance junction-ambient
UFQFPN28 - 4 x 4 mm
80 °C/W
Θ
JA
Thermal resistance junction-ambient
UFQFPN20 - 3 x 3 mm
102 °C/W
Θ
JA
Thermal resistance junction-ambient
TSSOP20
110 °C/W