Datasheet

DocID17659 Rev 9 121/131
STM32L151x6/8/B, STM32L152x6/8/B Package characteristics
130
7.2 Thermal characteristics
The maximum chip-junction temperature, T
J
max, in degrees Celsius, may be calculated
using the following equation:
T
J
max = T
A
max + (P
D
max × Θ
JA
)
Where:
• T
A
max is the maximum ambient temperature in °C,
•Θ
JA
is the package junction-to-ambient thermal resistance, in °C/W,
• P
D
max is the sum of P
INT
max and P
I/O
max (P
D
max = P
INT
max + P
I/O
max),
• P
INT
max is the product of I
DD
and V
DD
, expressed in Watts. This is the maximum chip
internal power.
P
I/O
max represents the maximum power dissipation on output pins where:
P
I/O
max = 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 69. Thermal characteristics
Symbol Parameter Value Unit
Θ
JA
Thermal resistance junction-ambient
BGA100 - 7 x 7 mm
59
°C/W
Thermal resistance junction-ambient
LQFP100 - 14 x 14 mm / 0.5 mm pitch
46
Thermal resistance junction-ambient
TFBGA64 - 5 x 5 mm
65
Thermal resistance junction-ambient
LQFP64 - 10 x 10 mm / 0.5 mm pitch
45
Thermal resistance junction-ambient
LQFP48 - 7 x 7 mm / 0.5 mm pitch
55
Thermal resistance junction-ambient
UFQFPN48 - 7 x 7 mm / 0.5 mm pitch
16