DocID027290 Rev 1

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AN4635

Power consumption comparison

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Figure 11. HSI vs. MSI at 4 MHz

Note that the timing with MSI is slightly off in the transmission phase. This is a common

problem when MSI is used to clock the LPUART peripheral.

Table 13. Configurations - HSI vs. MSI

Curve in Figure 11

Black

Red

Idle mode between

transmissions

Stop

Sleep

JTAG interface

OFF

Current average

over phases 2, 3 and 4

17.39 µA

15.53 µA

Clock

4 MHz HSI

4 MHz MSI

Voltage regulator

Range 3

AHB/APB ratio

1/1

ULP/FWU

+/+