Espressif ESP32-S2 WROOM 32 bit LX7 CPU User Manual

Espressif ESP32-S2 WROOM 32 bit LX7 CPU

Specifications

• MCU: ESP32-S2
• Hardware: Wi-Fi
• Wi-Fi Frequency: 2412 ~ 2462 MHz

About This Document

• This document provides the specifications for the ESP32-S2-WROOM and ESP32-S2-WROOM-I module.

Document Updates

• Please always refer to the latest version on https://www.espressif.com/en/support/download/documents.

Revision History

• For revision history of this document, please refer to the last page.

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Certification

• Download certificates for Espressif products from www.espressif.com/en/certificates.

Disclaimer and Copyright Notice

• Information in this document, including URL references, is subject to change without notice. THIS DOCUMENT IS PROVIDED AS IS WITH NO WARRANTIES WHATSOEVER, INCLUDING ANY WARRANTY OF MERCHANTABIL-ITY, NON-INFRINGEMENT, FITNESS FOR ANY PARTICULAR PURPOSE, OR ANY WARRANTY OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION OR SAMPLE.
• All liability, including liability for infringement of any proprietary rights, relating to use of information in this docu-ment is disclaimed. No licenses express or implied, by estoppel or otherwise, to any intellectual property rights are granted herein. The Wi-Fi Alliance Member logo is a trademark of the Wi-Fi Alliance. The Bluetooth logo is a registered trademark of Bluetooth SIG.
• All trade names, trademarks and registered trademarks mentioned in this document are property of their respective owners, and are hereby acknowledged.
• Copyright © 2020 Espressif Systems (Shanghai) Co., Ltd. All rights reserved.

Module Overview

Features
MCU

• ESP32-S2 embedded, Xtensa® single-core 32-bit LX7 microprocessor, up to 240 MHz
• 128 KB ROM
• 320 KB SRAM
• 16 KB SRAM in RTC

Wi-Fi

• 802.11 b/g/n
• Bit rate: 802.11n up to 150 Mbps
• A-MPDU and A-MSDU aggregation
•  0.4 µs guard interval support
• Center frequency range of operating channel: 2412 ~ 2462 MHz

Hardware

• Interfaces: GPIO, SPI, LCD, UART, I2C, I2S, Cam-era interface, IR, pulse counter, LED PWM, USB OTG 1.1, ADC, DAC, touch sensor, temperature sensor
• 40 MHz crystal oscillator
• 4 MB SPI flash
• Operating voltage/Power supply: 3.0 ~ 3.6 V
• Operating temperature range : –40 ~ 85 °C
• Dimensions: (18 × 31 × 3.3) mm

Certification

• Green certification: RoHS/REACH
• RF certification : FCC/CE-RED/SRRC

Test

• HTOL/HTSL/uHAST/TCT/ESD

Description

• ESP32-S2-WROOM and ESP32-S2-WROOM-I are two powerful, generic Wi-Fi MCU modules that have a rich set of peripherals. They are an ideal choice for a wide variety of application scenarios relating to Internet of Things (IoT), wearable electronics and smart home.
• ESP32-S2-WROOM comes with a PCB antenna, and ESP32-S2-WROOM-I with an IPEX antenna. They both feature a 4 MB external SPI flash. The information in this datasheet is applicable to both modules.
  The ordering information of the two modules is listed as follows:

Table 1: Ordering Information

ESP32-S2-WROOM-I (IPEX)
Notes

1. The module with various capacities of flash is available for custom order.
2. For dimensions of the IPEX connector, please see Section 7.3.

• At the core of this module is ESP32-S2 *, an Xtensa® 32-bit LX7 CPU that operates at up to 240 MHz. The chip has a low-power co-processor that can be used instead of the CPU to save power while performing tasks that do not require much computing power, such as monitoring of peripherals. ESP32-S2 integrates a rich set of peripherals, ranging from SPI, I²S, UART, I²C, LED PWM, LCD, Camera interface, ADC, DAC, touch sensor, temperature sensor, as well as up to 43 GPIOs. It also includes a full-speed USB On-The-Go (OTG) interface to enable USB communication.

Note

• For more information on ESP32-S2, please refer to ESP32-S2 Datasheet.

 Applications

• Generic Low-power IoT Sensor Hub
• Generic Low-power IoT Data Loggers
• Cameras for Video Streaming
• Over-the-top (OTT) Devices
• USB Devices
• Speech Recognition
• Image Recognition
• Mesh Network
• Home Automation
• Smart Home Control Panel
• Smart Building
• Industrial Automation
• Smart Agriculture
• Audio Applications
• Health Care Applications
• Wi-Fi-enabled Toys
• Wearable Electronics
• Retail & Catering Applications
• Smart POS Machines

Pin Definitions

Pin Layout

Figure 1: Module Pin Layout (Top View)

Note
The pin diagram shows the approximate location of pins on the module. For the actual mechanical diagram, please refer to Figure 7.1 Physical Dimensions.

Pin Description

The module has 42 pins. See pin definitions in Table 2.
Espressif Systems

Table 2: Pin Definitions

Function

---|---|---|---
EN| 41| I| High: on, enables the chip. Low: off, the chip powers off.

Note : Do not leave the EN pin floating.

GND| 42| P| Ground

Notice
For peripheral pin configurations, please refer to ESP32-S2 User Manual.

Strapping Pins
ESP32-S2 has three strapping pins: GPIO0, GPIO45, GPIO46. The pin-pin mapping between ESP32-S2 and the module is as follows, which can be seen in Chapter 5 Schematics:

• GPIO0 = IO0
•  GPIO45 = IO45
• GPIO46 = IO46
• Software can read the values of corresponding bits from register ”GPIO_STRAPPING”.
• During the chip’s system reset (power-on-reset, RTC watchdog reset, brownout reset, analog super watchdog reset, and crystal clock glitch detection reset), the latches of the strapping pins sample the voltage level as strapping bits of ”0” or ”1”, and hold these bits until the chip is powered down or shut down.
• IO0, IO45 and IO46 are connected to the internal pull-up/pull-down. If they are unconnected or the connected external circuit is high-impedance, the internal weak pull-up/pull-down will determine the default input level of these strapping pins.
• To change the strapping bit values, users can apply the external pull-down/pull-up resistances, or use the host MCU’s GPIOs to control the voltage level of these pins when powering on ESP32-S2.
• After reset, the strapping pins work as normal-function pins.
  Refer to Table 3 for a detailed boot-mode configuration of the strapping pins.

Table 3: Strapping Pins

VDD_SPI Voltage 1

Pin| Default| 3.3 V| 1.8 V
IO45 2| Pull-down| 0| 1
Booting Mode
Pin| Default| SPI Boot| Download Boot
IO0| Pull-up| 1| 0
IO46| Pull-down| Don’t-care| 0
Enabling/Disabling ROM Code Print During Booting 3 4
Pin| Default| Enabled| Disabled
IO46| Pull-down| See the fourth note| See the fourth note

Note

1. Firmware can configure register bits to change the settings of ”VDD_SPI Voltage”.

2. Internal pull-up resistor (R1) for IO45 is not populated in the module, as the flash in the module works at 3.3 V by default (output by VDD_SPI). Please make sure IO45 will not be pulled high when the module is powered up by external circuit.

3. ROM code can be printed over TXD0 (by default) or DAC_1 (IO17), depending on the eFuse bit.

4. When eFuse UART_PRINT_CONTROL value is:
   print is normal during boot and not controlled by IO46.

5. and IO46 is 0, print is normal during boot; but if IO46 is 1, print is disabled.

6. nd IO46 is 0, print is disabled; but if IO46 is 1, print is normal.

7. print is disabled and not controlled by IO46.

Electrical Characteristics

Absolute Maximum Ratings

Table 4: Absolute Maximum Ratings

Symbol

| Parameter| Min| Max|

Unit

---|---|---|---|---
VDD33| Power supply voltage| –0.3| 3.6| V
T STORE| Storage temperature| –40| 85| °C

Recommended Operating Conditions

Table 5: Recommended Operating Conditions

Symbol

| Parameter| Min| Typ| Max|

Unit

---|---|---|---|---|---
VDD33| Power supply voltage| 3.0| 3.3| 3.6| V
I V DD| Current delivered by external power supply| 0.5| —| —| A
T| Operating temperature| –40| —| 85| °C
Humidity| Humidity condition| —| 85| —| %RH

DC Characteristics (3.3 V, 25 °C)

Table 6: DC Characteristics (3.3 V, 25 °C)

Symbol| Parameter| Min| Typ| Max|

Unit

---|---|---|---|---|---
C IN| Pin capacitance| —| 2| —| pF
V IH| High-level input voltage| 0.75 × VDD| —| VDD + 0.3| V
V IL| Low-level input voltage| –0.3| —| 0.25 × VDD| V
I I H| High-level input current| —| —| 50| nA
I I L| Low-level input current| —| —| 50| nA
V OH| High-level output voltage| 0.8 × VDD| —| —| V
V OL| Low-level output voltage| —| —| 0.1 × VDD| V
I OH| High-level source current (VDD = 3.3 V, V OH >=

2.64 V, PAD_DRIVER = 3)

| —| 40| —| mA
I O L| Low-level sink current (VDD = 3.3 V, V OL =

0.495 V, PAD_DRIVER = 3)

| —| 28| —| mA
R PU| Pull-up resistor| —| 45| —| kΩ
R PD| Pull-down resistor| —| 45| —| kΩ
V IH _ nRST| Chip reset release voltage| 0.75 × VDD| —| VDD + 0.3| V
V IL _ nRST| Chip reset voltage| –0.3| —| 0.25 × VDD| V

Note
VDD is the I/O voltage for a particular power domain of pins.

Current Consumption Characteristics
With the use of advanced power-management technologies, the module can switch between different power modes. For details on different power modes, please refer to Section RTC and Low-Power Management in ESP32-S2 User Manual.

Table 7: Current Consumption Depending on RF Modes

Work mode

| Description| Average|

Peak

---|---|---|---
Active (RF working)|

TX

| 802.11b, 20 MHz, 1 Mbps, @ 22.31dBm| 190 mA| 310 mA
802.11g, 20 MHz, 54 Mbps, @ 25.00dBm| 145 mA| 220 mA
802.11n, 20 MHz, MCS7, @ 24.23dBm| 135 mA| 200 mA
802.11n, 40 MHz, MCS7, @ 22.86 dBm| 120 mA| 160 mA
RX| 802.11b/g/n, 20 MHz| 63 mA| 63 mA
802.11n, 40 MHz| 68 mA| 68 mA

Note

• The current consumption measurements are taken with a 3.3 V supply at 25 °C of ambient temperature at the RF port. All transmitters’ measurements are based on a 50% duty cycle.
• The current consumption figures for in RX mode are for cases when the peripherals are disabled and the CPU idle.

Table 8: Current Consumption Depending on Work Modes

Note

• The current consumption figures in Modem-sleep mode are for cases where the CPU is powered on and the cache idle.
• When Wi-Fi is enabled, the chip switches between Active and Modem-sleep modes. Therefore, current consump-tion changes accordingly.
• In Modem-sleep mode, the CPU frequency changes automatically. The frequency depends on the CPU load and the peripherals used.
• During Deep-sleep, when the ULP co-processor is powered on, peripherals such as GPIO and I²C are able to operate.
• The ”ULP sensor-monitored pattern” refers to the mode where the ULP coprocessor or the sensor works periodi-cally. When touch sensors work with a duty cycle of 1%, the typical current consumption is 7 µA.

Wi-Fi RF Characteristics
Wi-Fi RF Standards

Table 9: Wi-Fi RF Standards

Name

|

Description

---|---
Center frequency range of operating channel note 1| 2412 ~ 2462 MHz
Wi-Fi wireless standard| IEEE 802.11b/g/n
Data rate| 20 MHz| 11b: 1, 2, 5.5 and 11 Mbps

11g: 6, 9, 12, 18, 24, 36, 48, 54 Mbps

11n: MCS0-7, 72.2 Mbps (Max)

40 MHz| 11n: MCS0-7, 150 Mbps (Max)
Antenna type| PCB antenna, IPEX antenna

1. Device should operate in the center frequency range allocated by regional regulatory authorities. Target center frequency range is configurable by software.
2.  For the modules that use IPEX antennas, the output impedance is 50 Ω. For other modules without IPEX antennas, users do not need to concern about the output impedance.

Transmitter Characteristics

Table 10: Transmitter Characteristics

802.11g:25.00dBm

802.11n20:24.23dBm

802.11n40:22.86dBm

| dBm

1. Target TX power is configurable based on device or certification requirements.

Receiver Characteristics

Table 11: Receiver Characteristics

Parameter

| Rate| Typ|

Unit

---|---|---|---
RX Sensitivity| 1 Mbps| –97|

dBm

2 Mbps| –95
5.5 Mbps| –93
11 Mbps| –88
6 Mbps| –92

Electrical Characteristics

Parameter

| Rate| Typ|

Unit

---|---|---|---
RX Sensitivity| 9 Mbps| –91| dBm
12 Mbps| –89
18 Mbps| –86
24 Mbps| –83
36 Mbps| –80
48 Mbps| –76
54 Mbps| –74
11n, HT20, MCS0| –92
11n, HT20, MCS1| –88
11n, HT20, MCS2| –85
11n, HT20, MCS3| –82
11n, HT20, MCS4| –79
11n, HT20, MCS5| –75
11n, HT20, MCS6| –73
11n, HT20, MCS7| –72
11n, HT40, MCS0| –89
11n, HT40, MCS1| –85
11n, HT40, MCS2| –83
11n, HT40, MCS3| –79
11n, HT40, MCS4| –76
11n, HT40, MCS5| –72
11n, HT40, MCS6| –70
11n, HT40, MCS7| –68
RX Maximum Input Level| 11b, 1 Mbps| 5| dBm
11b, 11 Mbps| 5
11g, 6 Mbps| 5
11g, 54 Mbps| 0
11n, HT20, MCS0| 5
11n, HT20, MCS7| 0
11n, HT40, MCS0| 5
11n, HT40, MCS7| 0
Adjacent Channel Rejection| 11b, 11 Mbps| 35|

dB

11g, 6 Mbps| 31
11g, 54 Mbps| 14
11n, HT20, MCS0| 31
11n, HT20, MCS7| 13
11n, HT40, MCS0| 19
11n, HT40, MCS7| 8

Physical Dimensions and PCB Land Pattern

Physical Dimensions

Figure 6: Physical Dimensions

Recommended PCB Land Pattern

Figure 7: Recommended PCB Land Pattern

U.FL Connector Dimensions

Product Handling

Storage Condition

• The products sealed in Moisture Barrier Bag (MBB) should be stored in a noncondensing atmospheric environment of < 40 °C/90%RH.
• The module is rated at moisture sensitivity level (MSL) 3.
• After unpacking, the module must be soldered within 168 hours with factory conditions 25±5 °C/60%RH. The module needs to be baked if the above conditions are not met.

ESD

• Human body model (HBM): 2000 V
• Charged-device model (CDM): 500 V
• Air discharge: 6000 V
• Contact discharge: 4000 V

Reflow Profile

Figure 9: Reflow Profile

Note
Solder the module in a single reflow. If the PCBA requires multiple reflows, place the module on the PCB during the final reflow.

 MAC Addresses and eFuse

The eFuse in ESP32-S2 has been burnt into 48-bit mac_address. The actual addresses the chip uses in station and AP modes correspond to mac_address in the following way:

• Station mode: mac_address
• AP mode : mac_address + 1
• There are seven blocks in eFuse for users to use. Each block is 256 bits in size and has independent write/read disable controller. Six of them can be used to store encrypted key or user data, and the remaining one is only used to store user data.

Antenna Specifications

PCB Antenna
Model: ESP ANT B

Assembly: PTH Gain:

Dimensions

Pattern Plots

IPEX Antenna

Specifications

Gain

Directivity Diagram

Dimensions

Learning Resources

Must-Read Documents
The following link provides documents related to ESP32-S2.

• ESP32-S2 User Manual
  This document provides an introduction to the specifications of the ESP32-S2 hardware, including overview, pin definitions, functional description, peripheral interface, electrical characteristics, etc.

• ESP-IDF Programming Guide
  It hosts extensive documentation for ESP-IDF ranging from hardware guides to API reference.

• ESP32-S2 Technical Reference Manual
  The manual provides detailed information on how to use the ESP32-S2 memory and peripherals.

• Espressif Products Ordering Information

Must-Have Resources
Here are the ESP32-S2-related must-have resources.

ESP32-S2 BBS

• This is an Engineer-to-Engineer (E2E) Community for ESP32-S2 where you can post questions, share knowl-edge, explore ideas, and help solve problems with fellow engineers.

Revision History

References

• Wireless SoCs, Software, Cloud and AIoT Solutions | Espressif Systems
• Certificates | Espressif Systems
• Subscribe | Espressif Systems
• Page Not Found - ESP32 - — ESP-IDF Programming Guide latest documentation
• ESP32 Forum - Index page
• Documentation Feedback | Espressif Systems

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