AN4991 · Application noteHow to wake up an STM32 microcontroller from low-power mode with the USART or the LPUART
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Conclusion

Conclusion

This application note explains how the USART or the LPUART wakes up an STM32 MCU from a low-power mode. It also provides guidelines to approximately determine the associated USART/LPUART maximum baudrate.

Revision history

Table 7. Document revision history
DateVersionChanges
8-Mar-20171Initial release.
17-Dec-20192Updated microcontroller list in:
  • Title of the document
  • Table 1: Applicable products
  • Section 5.2: USART/LPUART HSI kernel clock is OFF in low-power mode

Added Section 1: General information (Arm logo added)

Updated:
  • Table 2: Low-power modes versus STM32xx Series
  • Section 5.1.1: HSI clock used as USART/LPUART clock source
  • Section 5.1.2: LSE clock used as LPUART clock source
8-Dec-20223STM32U5 Series inserted in this document
Updated
  • Document title
  • Table 1. Applicable products
  • Section 2 STM32 low-power modes
  • Section 3.2 USART/LPUART wake-up sources
  • Section 4 How the USART/PLUART wakes up the STM32 with new Section 4.2
  • Section 5.1.1 Internal oscillator clock used as USART/LPUART clock source
14-Dec-20224Updated:
  • Table 1. Applicable products to include the STM32C0 Series
  • Table 2. STM32 low-power modes
  • Table 3. STM32 internal oscillators
16-Jan-20235Updated:
  • Table 1. Applicable products to include the STM32WBA series
  • Table 2. STM32 low-power modes
  • Table 3. STM32 internal oscillators
05-Sep-20246Added support for STM32H5 series, STM32H7 series, STM32N6 series, and STM32WB0 series.
14-Feb-20257Added STM32U0 series and STM32U3 series.
Updated: