STM8T141 Datasheet, PDF (23/50 Pages) STMicroelectronics – On-chip integrated voltage regulator

STM8T141
Device operation
7.4
Power modes
The STM8T141 device offers four power modes. The low power modes are specifically
designed for battery applications:
● Normal Power mode
● Low Power mode with Zoom
● Extreme Low Power mode with Zoom
● Extreme Low Power mode
Burst cycles can occur either every 10 ms or 20 ms according to the selected sampling
period (t_SAMPLING). By selecting low power modes, extra delays are interlaced between
bursts. This improves the device current consumption at the expense of the response time.
Bits [7:6] of option byte OPT0 are used to select the correct power mode.
Table 8. Low power period according to selected power mode
Power mode
Condition
t_LP value
Normal Power mode
0
Low Power mode with Zoom
Touch or proximity detection
Untouched
Extreme Low Power mode with ^{Touch or proximity detection}
Zoom
Untouched
Extreme Low Power mode
0
4 x t_SAMPLING
0
16 x t_SAMPLING
16 x t_SAMPLING
7.4.1
Normal Power mode
When in Normal Power mode, burst cycles occur at the rate of t_SAMPLING. No extra delays
are added between burst cycles (Figure 16).
Figure 16. Charge cycle timing diagram in Normal Power mode
C_S
Burst cycle duration
t
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Doc ID 15699 Rev 7
23/50