AN2857 datasheet(18/31 Pages) STMICROELECTRONICS

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Power consumption and wakeup time measurements and results

AN2857

18/31

Doc ID 15241 Rev 3

Power consumption and wakeup time measurements

and results

The following measurements and results aim to highlight the impact of different low-power

modes on MCU consumption and wakeup time.

Power consumptions given are typical values measured at 25 °C. They are for guidance

only. A zip file containing the software used to take these measurements is attached to this

application note. Refer to the electrical characteristics sections of the STM8S and STM8A

datasheets for real specifications.

5.1

Power consumption measurements and results

Power consumption measurements are taken in run mode and low power modes. Results

are given in Table 5 to Table 10.

5.1.1

Measurement configuration

●

VDDA, VDDIO1, VDDIO2, and VDD are connected together to VDD

●

VSSA, VSSIO1, VSSIO2, and VSS are connected together to VSS

●

All ports are set as output low level (single wire interface module, SWIM, is disabled).

●

All peripherals are disabled (even if enabled by default)

●

If possible, all peripheral clocks are stopped (see the CLK_PCKENRx definition in the

STM8S and STM8A reference manual).

Once the device is configured, the MCU is then put into the different functioning modes

described in Section 4: Run and low-power modes. Measurements are performed on an

STM8S208MBT6 in an LQFP80 package. This is the ‘super set’ of the family which has the

highest consumption rates.

Hardware environment

Run and low-power modes power consumption are measured simultaneously on VDD,

VDDIO and VDDA. The hardware configuration is given in Figure 4: ITOT = IVDDIO + IVDD +

IVDDA.

AN2857 Datasheet(PDF) 18 Page - STMicroelectronics