Data Sheet

Table Of Contents
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
LDOLDO LDO1.8 V 1.1 V1.1 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.
Espressif Systems 18
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ESP32 Series Datasheet v3.5