Skip to main content
Explorer
September 8, 2025
Question

STM32U375RGT6Q - UART function

  • September 8, 2025
  • 6 replies
  • 448 views

Hi,

Will PC0 PC1 LPUART functions in normal operation? 

I have to use this LPUART in normal operation of MCU, not in power saving mode.

Is there any limitation on this like speed, baud rate etc. 

Regards,

Anurag

 

 

 

 

    This topic has been closed for replies.

    6 replies

    ST Employee
    September 8, 2025

    ShirleyYe_0-1757315614017.png

    from the reference manual, it can reach higher frequence if clock sources different from the LSE clock

    ST Employee
    September 8, 2025

    Hello,

    Just one point to add: the latest cube firmware for STM32U3 contains a working example of LPUART communication, without any low power modes.

    The example "LPUART_TwoBoards_ComIT" can be found by navigating the example selector in STM32CubeMX.

    It could serve as a good starting point to test if the LPUART fits your intended use case.

    Explorer
    September 11, 2025

    Hi,

    We are using STM32U375RGT6Q.

    Power 2.5V

    When internal oscillator used 4MHz, it takes less power, less than 0.5mA.

    When shift to external oscillator 4MHz, internal used clock 2MHz, it takes more power, greater than 1.5mA.

    We have to use external oscillator for measurement accuracy. 

    We have to reduce the MCU current on 2.5V with external oscillator, crystal used.

    Can you suggest possible ways to reduce power consumption.

    Input voltage for device is 5V 1mA. Used buck converter for 2.5V 85% efficiency. 

    Regards,

    Anurag

     

     

     

     

     

    Explorer
    September 15, 2025

    Hi,

    Can we use 2MHz external crystal for STM32U375RGT6Q? for low power consumption. 

    Though it is not given in datasheet.

     

    Regards,

    Anurag

     

    Graduate
    September 15, 2025

    If low power is a concern, why don't you use MSI internal oscillator synchronized to LSE?

    Explorer
    September 17, 2025

    Hi,

    Thanks!

    Does this solution has impact of temperature on accuracy? 

    Or it has nearly accuracy of LSE external crystal?

     

    Graduate
    September 17, 2025

    It has exactly the accuracy of the 32768 Hz crystal. Why don't you read the RCC section of RefMan?