STM32WL33C8 datasheet(13/91 Pages) STMICROELECTRONICS

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STATIC BYPASS ON THE FLY

–

the VFBSD pin is internally connected to VDDSD via a switch, with a maximum current of 40 mA

–

the SMPS doesn’t need a clock and is disabled

•

DYNAMIC BYPASS ON THE FLY

–

the VFBSD pin internally connected to the output of a programmable voltage regulator, with a

maximum current of 40mA.

–

the SMPS doesn’t need a clock and is disabled

Except for the configuration SMPS OFF, an L/C BOM must be present on the board and connected to the VFBSD

pad.

Figure 6. Power supply configuration

3.5.2

SMPS bypass on-the-fly (BOF)

Bypass on-the-fly (BOF) is a feature that allows the SMPS to be bypassed. This can be done directly with a power

switch (static bypass mode), or via an LDO (dynamic bypass mode).

In case extra radio sensitivity is needed, the user can switch to dynamic bypass mode before entering radio

receiver mode. In this way the SPSM is OFF. When BOF is done in static bypass mode, the SMPS is disabled

and the SMPS output is connected to the battery via an internal switch. In this case both Deepstop and Run mode

operations can be chosen.

When BOF is done in dynamic bypass mode, the SMPS is disabled and the LDO is enabled. The LDO is

connected between the battery and the VFBSD pin and its output voltage is programmable like the SMPS.

A current limitation is implemented in both static and dynamic bypass modes.

STM32WL33xx

Functional overview

DS14221 - Rev 5

page 13/91

STM32WL33C8 データシート(PDF) 13 Page - STMicroelectronics