The Doc whom IoT Professionals trust

Kategorie: ESP32

Reading Time: 2 Minutes


The data sheet of the ESP32 states its electrical characteristics (cf. esp32_datasheet_en.pdf). It specifies the absolute maximum ratings and the recommended ratings of the supply voltage applied to the power supply pins (cf. Conclusion).

Absolute Maximum Ratings

The absolute maximum rating of the voltage applied to the power supply pins VDDA, VDD3P3_RTC, VDD3P3, VDD3P3_CPU, and VDD_SDIO is between a minimum voltage of -0.3 volts and a maximum voltage of 3.6 volts. Please note that a voltage below or above the absolute maximum rating may cause a permanent damage to the ESP32 chip.

SymbolParameterMinMaxUnit
VDDA, VDD3P3_RTC, VDD3P3, VDD3P3_CPU,
and VDD_SDIO
Voltage applied to power supply pins-0.33.6V
Espressif ESP32 Data Sheet (cf. Table 11)

The recommended rating of the voltage applied to the power supply pins VDDA, VDD3P3_RTC, VDD3P3, and VDD_SDIO depends on the presence of a 3.3V flash embedded (cf. Ordering Information):

  • The ESP32 chip with the ordering code ESP32-U4WDH has a 4 MB embedded flash (80 MHz). As a result, the applied voltage is between a minimum voltage of 3.0 volts and a maximum voltage of 3.6 volts with a typical voltage of 3.3 volts.
  • The ESP32 chips with the ordering codes ESP32-D0WD-V3, ESP32-D0WDQ6-V3, ESP32-D0WD, ESP32-D0WDQ6, and ESP32-S0WD have no embedded flash. As a result, the applied voltage is between a minimum voltage of 2.3 volts and a maximum voltage of 3.6 volts with a typical voltage of 3.3 volts.

Be aware in both cases that writing to eFuse, the voltage applied to the power supply pin VDD3P3_RTC should be at least 3.3 volts.

The recommended rating of the voltage applied to the power supply pin VDD3P3_CPU is between a minimum voltage of 1.8 volts and a maximum voltage of 3.6 volts with a typical voltage of 3.3 volts.

SymbolParameterMinTypMaxUnit
VDDA, VDD3P3_RTC, VDD3P3, and VDD_SDIOVoltage applied to power supply pins2.3 / 3.03.33.6V
VDD3P3_CPUVoltage applied to power supply pin1.83.33.6V
Espressif ESP32 Data Sheet (cf. Table 12)

Conclusion

The operating voltage applied to the power supply pins ranges from 1.8 / 2.3 / 3.0 volts to 3.6 volts, where the recommended voltage of the power supply is 3.3 volts. Moreover, the recommended current delivered by external power supply 500 milliampere (or even more).


Release Notes:

  • [2021-09-04] Initial release of the blog post comprising the specifications of the absolute maximum ratings and the recommended ratings of the supply voltage applied to the power supply pins.

Deep Dive on the ESP32-S from Ai-Thinker

Reading Time: 3 Minutes

The ESP32-S from Ai-Thinker is a small-size, low-power wireless module for a wide variety of applications like a low-power sensor with a demanding task such as voice encoding. It is based on the famous ESP32 from Espressif, more precisely the ESP32-D0WDQ6 chip, designed to be scalable and adaptive. Please have a look at the following post for an in-detail description of the related features and specifications of the ESP32 chip (coming soon). The ESP32-S is Ai-Thinker’s equivalent to the ESP32-WROOM-32 module from Espressif, equaling in the form factor and specifications.

ESP32-S Front-View
Front View (Source)
ESP32-S Back View
Back View (Source)

Pin Definitions

ESP32-S Pin Layout
ESP32-S Pin-Out

The ESP32-S has a length of 18 mm, a width of 25.5 mm and a height of 2.8 mm ∓ 0.1 mm. Furthermore, it has 38 pins, defined as follows (cf. Datasheet):

The following table shows the name, type, number and function of the pins on the left-side of the ESP32-S:

ESP32-S Pin-Out
NameTypeGPIOFunction
GNDPGround
3V3PPower Supply: 3.3V (VDD), 500 mA
ENIChip-enable Signal (Active high)
SENSOR_VPIADC_H, ADC1_CH0, RTC_GPIO0
SENSOR_VNIADC1_CH3, ADC_H, RTC_GPIO3
IO34IGPIO34ADC1_CH6, RTC_GPIO4
IO35IGPIO35ADC1_CH7, RTC_GPIO5
IO32I/OGPIO32XTAL_32K_P (32.768kHz crystal oscillator input), ADC1_CH4, TOUCH9, RTC_GPIO9
IO33I/OGPIO33XTAL_32K_N (32.768kHz crystal oscillator output), ADC1_CH5, TOUCH8, RTC_GPIO8
IO25I/OGPIO25DAC_1, ADC2_CH8, RTC_GPIO6, EMAC_RXD0
IO26I/OGPIO26DAC_2, ADC2_CH9, RTC_GPIO7, EMAC_RXD1
IO27I/OGPIO27ADC2_CH7, TOUCH7, RTC_GPIO17, EMAC_RX_DV
IO14I/OGPIO14ADC2_CH6, TOUCH6, RTC_GPIO16, MTMS, HSPICLK, HS2_CLK, SD_CLK, EMAC_TXD2
IO12I/OGPIO12ADC2_CH5, TOUCH5, RTC_GPIO15, MTDI, HSPIQ, HS2_DATA2, SD_DATA2, EMAC_TXD3
Mapping of the pins at the left-side of the ESP32-S

The following table shows the name, type, number and function of the pins on the bottom of the ESP32-S:

ESP32-S Pin-Out
NameTypeGPIOFunction
GNDPGround
IO13I/OGPIO13ADC2_CH4, TOUCH4, RTC_GPIO14, MTCK, HSPID, HS2_DATA3, SD_DATA3, EMAC_RX_ER
SHD/SD2I/OGPIO9SD_DATA2, SPIHD, HS1_DATA2, U1RXD
SWP/SD3I/OGPIO10SD_DATA3, SPIWP, HS1_DATA3, U1TXD
SCS/CMDI/OGPIO11SD_CMD, SPICS0, HS1_CMD, U1RTS
SCK/CLKI/OGPIO6SD_CLK, SPICLK, HS1_CLK, U1CTS
SDO/SD0I/OGPIO7SD_DATA0, SPIQ, HS1_DATA0, U2RTS
SDI/SD1I/OGPIO8SD_DATA1, SPID, HS1_DATA1, U2CTS
IO15I/OGPIO15ADC2_CH3, TOUCH3, MTDO, HSPICS0, RTC_GPIO13, HS2_CMD, SD_CMD, EMAC_RXD3
IO2I/OGPIO2ADC2_CH2, TOUCH2, RTC_GPIO12, HSPIWP, HS2_DATA0, SD_DATA0
Mapping of the pins at the botom of the ESP32-S

The following table shows the name, type, number and function of the pins on the right-side of the ESP32-S:

ESP32-S Pin-Out
NameTypeGPIOFunction
IO0I/OGPIO0ADC2_CH1, TOUCH1, RTC_GPIO11, CLK_OUT1, EMAC_TX_CLK
IO4I/OGPIO4ADC2_CH0, TOUCH0, RTC_GPIO10, HSPIHD, HS2_DATA1, SD_DATA1, EMAC_TX_ER
IO16I/OGPIO16HS1_DATA4, U2RXD, EMAC_CLK_OUT
IO17I/OGPIO17HS1_DATA5, U2TXD, EMAC_CLK_OUT_180
IO5I/OGPIO5VSPICS0, HS1_DATA6, EMAC_RX_CLK
IO18I/OGPIO18VSPICLK, HS1_DATA7
IO19I/OGPIO19VSPIQ, U0CTS, EMAC_TXD0
NC
IO21I/OGPIO21VSPIHD, EMAC_TX_EN
RXD0I/OGPIO3U0RXD, CLK_OUT2
TXD0I/OGPIO1U0TXD, CLK_OUT3, EMAC_RXD2
IO22I/OGPIO22VSPIWP, U0RTS, EMAC_TXD1
IO23I/OGPIO23VSPID, HS1_STROBE
GNDPGround
Pin Mapping

Modules and Functions

(coming soon)

Electrical Characteristics

(coming soon)

Schematic Diagram

ESP32-S Schematic Diagram
Schematic Diagram of the ESP32-S (Source)

© 2024 Dr. Mountain

Theme von Anders NorénHoch ↑