Datasheet

Package characteristics STM32F303xB STM32F303xC
128/133 DocID023353 Rev 7
Example 2: High-temperature application
Using the same rules, it is possible to address applications that run at high ambient
temperatures with a low dissipation, as long as junction temperature T
J
remains within the
specified range.
Assuming the following application conditions:
Maximum ambient temperature T
Amax
= 115 °C (measured according to JESD51-2),
I
DDmax
= 20 mA, V
DD
= 3.5 V, maximum 9 I/Os used at the same time in output at low
level with I
OL
= 8 mA, V
OL
= 0.4 V
P
INTmax
= 20 mA × 3.5 V= 70 mW
P
IOmax
= 9 × 8 mA × 0.4 V = 28.8 mW
This gives: P
INTmax
= 70 mW and P
IOmax
= 28.8 mW:
P
Dmax
= 70 + 28.8 = 98.8 mW
Thus: P
Dmax
= 98.8 mW
Using the values obtained in Table 79 T
Jmax
is calculated as follows:
– For LQFP100, 41°C/W
T
Jmax
= 115 °C + (41°C/W × 98.8 mW) = 115 °C + 4.05 °C = 119.05 °C
This is within the range of the suffix 7 version parts (–40 < T
J
< 125 °C).
In this case, parts must be ordered at least with the temperature range suffix 7 (see
Section 8: Part numbering).