ESP32 datasheet(18/64 Pages) ESPRESSIF

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2. Pin Deﬁnitions

2.3 Power Scheme

ESP32’s digital pins are divided into three different power domains:

• VDD3P3_RTC

• VDD3P3_CPU

• VDD_SDIO

VDD3P3_RTC is also the input power supply for RTC and CPU.

VDD3P3_CPU is also the input power supply for CPU.

VDD_SDIO connects to the output of an internal LDO whose input is VDD3P3_RTC. When VDD_SDIO is connected

to the same PCB net together with VDD3P3_RTC, the internal LDO is disabled automatically. The power scheme

diagram is shown below:

SDIO

Domain

RTC

Domain

CPU

Domain

LDO

1.8 V

1.1 V

VDD3P3_RTC

VDD3P3_CPU

VDD_SDIO

3.3 V/1.8 V

Figure 4: ESP32 Power Scheme

The internal LDO can be configured as having 1.8 V, or the same voltage as VDD3P3_RTC. It can be powered off

via software to minimize the current of flash/SRAM during the Deep-sleep mode.

Notes on CHIP_PU:

• The illustration below shows the ESP32 power-up and reset timing. Details about the parameters are listed

in Table 2.

VDD

CHIP_PU

IL_nRST

VDD3P3_RTC Min

Figure 5: ESP32 Power-up and Reset Timing

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ESP32 Datasheet V3.4

ESP32 Datasheet(PDF) 18 Page - ESPRESSIF SYSTEMS (SHANGHAI) CO., LTD.