Datasheet

Package characteristics STM32F051x
100/105 Doc ID 022265 Rev 3
Figure 38. UFQFPN32 recommended footprint
1. Drawing is not to scale.
2. Dimensions are expressed in millimeters.
7.2 Thermal characteristics
The maximum chip junction temperature (T
J
max) must never exceed the values given in
Table 20: General operating conditions.
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 x 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.