AN4635 datasheet(12/34 Pages) STMICROELECTRONICS

Part #	AN4635

Description	Minimization of power consumption using LPUART in microcontrollers of the STM32L0 series

PDF	34 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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12 / 34 page

Other considerations

AN4635

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DocID027290 Rev 1

Additionally, in blocking mode, which requires the least CPU processing resources, it is

possible to take advantage of the low power run mode. This mode essentially bypasses the

main voltage regulator and powers the core with power consumption approximately another

25% lower than the range 3 of the main power regulator can achieve (Section 6.2).

But waking from Stop or Sleep mode brings the main regulator back on and considering the

current low clock speed (MSI range 1 at most) the core must immediately dedicate all

processing power to data reception. In practical terms the LPRUN is great for transmission

phase, but when waiting for data reception it is usually better to take advantage of the Stop

mode instead of keeping the CPU in LPRUN. It is however possible to put the main voltage

regulator temporarily to range 3 (it must be in range 2 when switch to LPRUN is done).

Changing configuration of main regulator is quicker than switching the regulator and less

likely to cause dropped bytes in incoming message.

AN4635 Datasheet(PDF) 12 Page - STMicroelectronics