Power consumption comparison

AN4635

26/34

DocID027290 Rev 1

Note:

The timing is slightly different for the 2 cases. This is a common problem when MSI is used

to clock the LPUART peripheral. MSI clock is generally less precise than LSE or even HSI.

6.10

Wakeup from Stop mode on HSI

Another option to use with higher communication speed is to exploit the feature of wakeup

from Stop mode with peripheral being clocked from the HSI clock (see Figure 11).

The HSI oscillator draws approximately as much current in combination with the Stop mode

as the MSI at 2 MHz requires in Sleep mode. It is however more precise and with provides

the core with more processing power in run mode.

Voltage regulator

Range 1

AHB/APB ratio

1/1

ULP/FWU

+/+

Baud rate

57600

SW used

Interrupt operation (Com IT)

modified with USART on SYSCLK

Interrupt operation (Com IT)

modified with LPUART on SYSCLK

Table 12. Configurations - Higher communication speed (continued)

Black

Red