STM32WB55 datasheet(28/193 Pages) STMICROELECTRONICS

Part #	STM32WB55

Description	Multiprotocol wireless 32-bit MCU Arm®-based Cortex®-M4 with FPU, Bluetooth® 5.2 and 802.15.4 radio solution

PDF	193 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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28 / 193 page

Functional overview

STM32WB55xx STM32WB35xx

28/193

DS11929 Rev 11

During power up/down, the following power sequence requirements must be respected:



When VDD is below 1 V the other power supplies (VDDA, VDDUSB, VLCD), must remain

below VDD + 300 mV



When VDD is above 1 V all power supplies are independent.

Figure 6. Power-up/down sequence

1. VDDX refers to any power supply among VDDA, VDDUSB and VLCD.

During the power down phase, VDD can temporarily become lower than other supplies only

if the energy provided to the MCU remains below 1 mJ. This allows the external decoupling

capacitors to be discharged with different time constants during the power down transient

phase.

Note:

VDD, VDDRF and VDDSMPS must be wired together, so they can follow the same voltage

sequence.

MSv47490V1

0.3

VBOR0

3.6

Operating mode

Power-on

Power-down

time

VDDX

(1)

VDD

Invalid supply area

VDDX < VDD + 300 mV

VDDX independent from VDD

STM32WB55 Datasheet(PDF) 28 Page - STMicroelectronics