STM32U375RGT6Q - UART function

[Anuraglokhande]

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

[Shirley.Ye]

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

[Jojo_]

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.

[Anuraglokhande]

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

[Anuraglokhande]

Hi,

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

Though it is not given in datasheet.

Regards,

Anurag

[gbm]

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

[Anuraglokhande]

Hi,

Thanks!

Does this solution has impact of temperature on accuracy? 

Or it has nearly accuracy of LSE external crystal?

[gbm]

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