Datasheet

Electrical parameters STM8L151xx, STM8L152xx
112/131 DocID15962 Rev 13
9.4 Thermal characteristics
The maximum chip junction temperature (T
Jmax
) must never exceed the values given in
Table 18: General operating conditions on page 64.
The maximum chip-junction temperature, T
Jmax
, in degree Celsius, may be calculated using
the following equation:
T
Jmax
= T
Amax
+ (P
Dmax
x 
JA
)
Where:
 T
Amax
is the maximum ambient temperature in C

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
= (V
OL
*I
OL
) + ((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 62. 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

JA
Thermal resistance junction-ambient
LQFP 48- 7 x 7 mm
65 °C/W

JA
Thermal resistance junction-ambient
UFQFPN 48- 7 x 7mm
32 °C/W

JA
Thermal resistance junction-ambient
LQFP 32 - 7 x 7 mm
59 °C/W

JA
Thermal resistance junction-ambient
UFQFPN 32 - 5 x 5 mm
38 °C/W

JA
Thermal resistance junction-ambient
UFQFPN28 - 4 x 4 mm
118 °C/W

JA
Thermal resistance junction-ambient
WLCSP28
70 °C/W