STM32F358XC datasheet(129/134 Pages) STMICROELECTRONICS

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STM32F358xC

Package information

131

7.4.2

Selecting the product temperature range

When ordering the microcontroller, the temperature range is specified in the ordering

information scheme shown in Section 8: Part numbering.

Each temperature range suffix corresponds to a specific guaranteed ambient temperature at

maximum dissipation and, to a specific maximum junction temperature.

As applications do not commonly use the STM32F358xC devices at the maximum

dissipation, it is useful to calculate the exact power consumption and junction temperature

to determine which temperature range will be best suited to the application.

The following examples show how to calculate the temperature range needed for a given

application.

Example 1: High-performance application

Assuming the following application conditions:

Maximum ambient temperature TAmax = 82 °C (measured according to JESD51-2),

IDDmax = 50 mA, VDD = 3.5 V, maximum 3 I/Os used at the same time in output at low

level with IOL = 8 mA, VOL= 0.4 V and maximum 2 I/Os used at the same time in output

at low level with IOL = 20 mA, VOL= 1.3 V

PINTmax = 50 mA × 3.5 V= 175 mW

PIOmax = 3 × 8 mA × 0.4 V + 2 × 20 mA × 1.3 V = 61.6 mW

This gives: PINTmax = 175 mW and PIOmax = 61.6 mW:

PDmax = 175 + 61.6 = 236.6 mW

Thus: PDmax = 236.6 mW

Using the values obtained in Table 80 TJmax is calculated as follows:

–

For LQFP64, 45°C/W

TJmax = 82 °C + (45°C/W × 236.6 mW) = 82 °C + 10.65 °C = 92.65 °C

This is within the range of the suffix 6 version parts (–40 < TJ < 105 °C).

In this case, parts must be ordered at least with the temperature range suffix 6 (see

Section 8: Part numbering).

STM32F358XC Datasheet(PDF) 129 Page - STMicroelectronics