DocID027290 Rev 1

19/34

AN4635

Power consumption comparison

33

Figure 5. Using the Stop during data reception

6.5

Different oscillator clock speeds

Using the MSI clock the application computing power and power consumption can be easily

tuned to imminent needs of the system. It is of course possible to change the clock settings

on the fly, during execution.

Figure 6 shows the test execution at 2 MHz (black line), 500 kHz (purple line) and 130 kHz

(green line). The difference is large, but using the Sleep mode between both transmitted

Table 7. Configurations - Stop during data reception

Curve in Figure 5

Black

Red

Idle mode between

transmissions

Stop

JTAG interface

OFF

Current average

5.70 µA (Rx only)

6.35 µA (Rx only)

Clock

4 MHz MSI

500 kHz MSI

Voltage regulator

Range 3

AHB/APB ratio

1/1

ULP/FWU

+/+

Baud rate

9600

SW used

Interrupt operation (Com IT) with defines RXSTOP and TXSLEEP