STM32WB55 datasheet(185/193 Pages) STMICROELECTRONICS

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DS11929 Rev 11

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STM32WB55xx STM32WB35xx

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Note:

With this given PD max user can find the TA max allowed for a given device temperature

range (order code suffix 7).

Suffix 7: TA max = TJ max - (47 °C / W × 447 mW) = 125 °C - 21 °C = 103 °C

Example 2: High-temperature application

Using the same rules, it is possible to address applications running at high ambient

temperatures with a low dissipation, as long as junction temperature TJ remains within the

specified range.

Assuming the following application conditions:

Maximum ambient temperature TA max = 100 °C (measured according to JESD51-2),

IDD max = 50 mA, VDD = 3.5 V, maximum 20 I/Os used at the same time in output at

low level with IOL = 8 mA, VOL= 0.4 V

PINT max = 50 mA × 3.5 V = 175 mW

PIO max = 20 × 8 mA × 0.4 V = 64 mW

This gives: PINTmax = 175 mW and PIO max = 64 mW

PD max = 175 + 64 = 239 mW

Thus: PD max = 239 mW

Using the values obtained in Table 106 TJ max is calculated as follows:

–

For UFQFPN48, 24.9 °C / W

TJ max = 100 °C + (24.9 °C / W × 239 mW) = 100 °C + 6 °C = 106 °C

This is above 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 7 (see

Section 8), unless user reduces the power dissipation to be able to use suffix 6 parts.

STM32WB55 Datasheet(PDF) 185 Page - STMicroelectronics