ESP-WROOM-02

ESP-WROOM-02 FO NO T RE R C NE O M W M (N E D RN ES ND D) IG ED NS Datasheet Version 3.4 Espressif Systems Copyright © 2022 www.espressif.com About This Guide This document provides introduction to the specifications of ESP-WROOM-02 hardware. Release Notes Date Version Release notes 2015.12 V0.5 First release. 2016.01 V0.6 Updated Section 3.2.2. 2016.02 V0.7 2016.04 V0.8 Updated the flash size and PAD (bottom) size. 2016.06 V0.9 Updated the flash size. 2016.06 V1.0 2016.08 V1.1 2016.11 V1.2 2016.11 V2.0 2016.12 V2.1 2017.02 V2.2 • Added Appendix—Notices. • Updated Chapter 1. • Added Appendix—Notices—B.5. • Updated Figure 2-1. Updated the operating temperature range. • Added Appendix—Learning Resources. • Added “ESP-WROOM-02 Peripheral Schematics” in Chapter 5. • Added Section 4.8 “Electrostatic Discharge”. • Updated Figure 5-1. ESP-WROOM-02 Schematics. • Changed the minimum working voltage from 3.0 V to 2.5 V. • Changed the power consumption during Deep-sleep from 10 μA to 20 μA. Updated Section 3.3. • Added the module's dimensional tolerance; 2017.04 V2.3 • Changed the input impedance value in Table 4-4 and 4-5 from 50 Ω to 39 + j6 Ω; • Added Figure 4-1 Reflow Profile. • Added Documentation Change Notification and the official link for downloading Product Certificates; • Updated the supply voltage to 2.7 V ~ 3.6 V; • Updated Figure 2-1 ESP-WROOM-02 Pin Layout and added a note to it; 2017.09 V2.4 • Updated Chapter 4: Collated electrical-characteristics-related data into Table 4-1; collated Wi-Fi-radio-related data into Table 4-2 and updated the output power parameters; • Updated Chapter 5 Schematics and added a note; • Added Chapter 6 Dimensions. • Deleted Appendix B—Notices. 2017.10 V2.5 Updated the note to ESP-WROOM-02 Peripheral Schematics in Chapter 5. Not Recommended For New Designs (NRND) Date Version Release notes • Deleted the note in Chapter 1; • Deleted the “RF certification” column and added a new “Certificates” section 2018.03 V2.6 with all acquired certifications listed in Table 1-1; • Updated Section 3.1 and Section 3.2; • Updated Figure 4-1. 2018.04 V2.7 2018.06 V2.8 Deleted the “Bluetooth certification” part in Table 1-1. • Updated Figure 1-1 and Figure 6-1; • Updated Chapter 1 for module size. • Updated Chapter 1 for module size, and add information of reliability test items; 2018.08 V2.9 • Updated Figure 6-1 Dimensions of ESP-WROOM-02; • Added Chapter 7 Recommended PCB Land Pattern; • Updated the cover page. 2019.08 V3.0 Updated Chapter 6 Peripheral Schematics. 2019.12 V3.1 2020.07 V3.2 2021.08 V3.3 Added the “Not Recommended For New Designs (NRND)” watermark and footers. 2022.03 V3.4 Added a link to RF certification in Table 1-1 • Added a note for the reflow profile; • Added feedback links. • Updated Note in Chapter 6; • Updated links in Appendix. Documentation Change Notification Espressif provides email notifications to keep customers updated on changes to technical documentation. Please subscribe at https://www.espressif.com/en/subscribe. Certification Download certificates for Espressif products from https://www.espressif.com/en/ certificates. Not Recommended For New Designs (NRND) Table of Contents 1. Overview ................................................................................................................................ 1 2. Pin Description ......................................................................................................................3 3. Functional Description ..........................................................................................................5 3.1. MCU .........................................................................................................................................5 3.2. Memory .................................................................................................................................... 5 3.2.1. Internal SRAM and ROM ...........................................................................................5 3.2.2. SPI Flash .................................................................................................................... 5 3.3. Crystal Oscillator ...................................................................................................................... 6 3.4. Interface Description ................................................................................................................6 4. Electrical Characteristics ...................................................................................................... 8 4.1. Electrical Characteristics ..........................................................................................................8 4.2. Wi-Fi Radio ...............................................................................................................................8 4.3. Power Consumption ................................................................................................................. 9 4.4. Reflow Profile .........................................................................................................................10 4.5. Electrostatic Discharge ..........................................................................................................11 5. Schematics ..........................................................................................................................12 6. Peripheral Schematics ........................................................................................................13 7. Dimensions ..........................................................................................................................14 8. Recommended PCB Land Pattern ..................................................................................... 15 A. Appendix—Learning Resources .........................................................................................16 A.1. Must-Read Documents ..........................................................................................................16 A.2. Must-Have Resources ............................................................................................................17 Not Recommended For New Designs (NRND) 1. Overview # 1. Overview Espressif provides the SMD module—ESP-WROOM-02 that integrates ESP8266EX. The module has been adjusted to get the best RF performance. We recommend using ESPWROOM-02 for tests or for further development. 📖 Note: For more information on ESP8266EX, please refer to ESP8266EX Datasheet. The module size is (18.00 ± 0.10) mm x (20.00 ± 0.10) mm x (2.80 ± 0.10) mm. The type of flash used on this module is an SPI flash with a package size of SOP 8-150 mil. The gain of the on-board PCB antenna is 2 dBi. Figure 1-1. ESP-WROOM-02 Module
 Espressif Not Recommended For New Designs (NRND) #1/#18 2022.03 Submit Documentation Feedback 1. Overview # Table 1-1. ESP-WROOM-02 Specifications Categories Certification Test Wi-Fi Items Specifications RF certification See certificates for ESP-WROOM-02 Wi-Fi certifaction Wi-Fi Alliance Green certification RoHS, REACH Reliablity HTOL/HTSL/uHAST/TCT/ESD Wi-Fi protocols 802.11 b/g/n Frequency range 2.4 GHz ~ 2.5 GHz (2400 MHz ~ 2483.5 MHz) Peripheral interface Hardware Software Espressif UART/HSPI/I2C/I2S/IR Remote Control GPIO/PWM Operating voltage 2.7 V ~ 3.6 V Operating current Average: 80 mA Minimum current delivered by power supply 500 mA Operating temperature range –40 °C ~ 85 °C Storage temperature –40 °C ~ 85 °C Package size (18.00 ± 0.10) mm x (20.00 ± 0.10) mm x (2.80±0.10) mm External interface - Wi-Fi mode Station/SoftAP/SoftAP + Station Security WPA/WPA2 Encryption WEP/TKIP/AES Firmware upgrade UART Download/OTA (via network)/Download and write firmware via host Software development Supports Cloud Server Development/SDK for custom firmware development Network protocols IPv4, TCP/UDP/HTTP/FTP User configuration AT Instruction Set, Cloud Server, Android/iOS app Not Recommended For New Designs (NRND) #2/#18 2022.03 Submit Documentation Feedback 2. Pin Description # 2. Pin Description Figure 2-1 shows the pin distribution of the ESP-WROOM-02. PCB ANTENNA 1 3V3 GND 18 2 EN IO16 17 3 IO14 TOUT 16 4 IO12 RST 15 5 IO13 IO5 14 6 IO15 GND 13 7 IO2 TXD 12 8 IO0 RXD 11 9 GND IO4 10 19 GND # Figure 2-1. ESP-WROOM-02 Pin Layout (Top View) ESP-WROOM-02 has 18 pins. Please see the pin definitions in Table 2-1. Table 2-1. ESP-WROOM-02 Pin Definitions No. Pin Name Functional Description 3.3 V power supply (VDD) Espressif 📖 Note: 1 3V3 2 EN Chip enable pin. Active high. 3 IO14 GPIO14; HSPI_CLK 4 IO12 GPIO12; HSPI_MISO 5 IO13 GPIO13; HSPI_MOSI; UART0_CTS It is recommended the maximum output current a power supply provides be of 500 mA or above. Not Recommended For New Designs (NRND) #3/#18 2022.03 Submit Documentation Feedback 2. Pin Description # No. Pin Name 6 IO15 7 IO2 Functional Description GPIO15; MTDO; HSPICS; UART0_RTS Pull down. GPIO2; UART1_TXD Floating (internal pull-up) or pull up. GPIO0 8 IO0 • UART download: pull down. • Flash boot: floating or pull up. Espressif 9 GND GND 10 IO4 GPIO4 11 RXD 12 TXD 13 GND GND 14 IO5 GPIO5 15 RST Reset 16 TOUT It can be used to test the power-supply voltage of VDD3P3 (Pin3 and Pin4) and the input power voltage of TOUT (Pin6). These two functions cannot be used simultaneously. 17 IO16 GPIO16; used for Deep-sleep wake-up when connected to RST pin. 18 GND GND UART0_RXD, receive end in UART download; GPIO3 UART0_TXD, transmit end in UART download, floating or pull up; GPIO1 Not Recommended For New Designs (NRND) #4/#18 2022.03 Submit Documentation Feedback 3. Functional Description # 3. Functional Description 3.1. MCU ESP8266EX integrates a Tensilica L106 32-bit RISC processor, which achieves extra-low power consumption and reaches a maximum clock speed of 160 MHz. The Real-Time Operating System (RTOS) and Wi-Fi stack allow 80% of the processing power to be available for user application programming and development. The CPU includes the interfaces as below. • Programmable RAM/ROM interfaces (iBus), which can be connected with memory controller, and can also be used to visit flash. • Data RAM interface (dBus), which can connected with memory controller. • AHB interface which can be used to visit the register. 3.2. Memory 3.2.1. Internal SRAM and ROM ESP8266EX Wi-Fi SoC integrates memory controller and memory units including SRAM and ROM. MCU can access the memory units through iBus, dBus, and AHB interfaces. All memory units can be accessed upon request, while a memory arbiter will decide the running sequence according to the time when these requests are received by the processor. According to our current version of SDK, SRAM space available to users is assigned as below. • RAM size < 50 kB, that is, when ESP8266EX is working under the Station mode and connects to the router, programmable space accessible in heap + data section is around 50 kB. • There is no programmable ROM in the SoC, therefore, user program must be stored in an external SPI flash. 3.2.2. SPI Flash ESP8266EX uses external SPI flash to store user programs, and supports up to 16 MB memory capacity theoretically. ESP-WROOM-02 currently integrates a 2-MB SPI flash. ESP-WROOM-02 supports these SPI modes: Standard SPI, DIO (Dual I/O), DOUT (Dual Output), QIO (Quad I/O) and QOUT (Quad Output). Espressif Not Recommended For New Designs (NRND) #5/#18 2022.03 Submit Documentation Feedback 3. Functional Description # 3.3. Crystal Oscillator ESP-WROOM-02 uses a 26-MHz crystal oscillator. The accuracy of the crystal oscillator should be ±10 PPM. When using the download tool, please select the right type of crystal oscillator. In circuit design, capacitors C1 and C2 which connect to the earth are added to the input and output terminals of the crystal oscillator respectively. The values of the two capacitors can be flexible, ranging from 6 pF to 22 pF, however, the specific capacitive values depend on further testing of, and adjustment to, the overall performance of the whole circuit. Normally, the capacitive values of C1 and C2 are within 10 pF for the 26-MHz crystal oscillator. 3.4. Interface Description Table 3-1. Interface Description Interface Pin Functional Description HSPI IO12 (MISO), IO13 (MOSI), IO14 (CLK), IO15 (CS) Connects to SPI Flash, display screen, and MCU. PWM IO12 (R), IO15 (G), IO13 (B) Currently the PWM interface has four channels, but users can extend it to eight channels. PWM interface can realize the control of LED lights, buzzers, relays, electronic machines, etc. IR The functionality of the infrared remote control interface can be realized via software programming. The interface uses NEC coding, modulation, IO14 (IR_T), IO5 (IR_R) and demodulation. The frequency of the modulated carrier signal is 38 kHz. ADC TOUT I2C IO14 (SCL), IO2 (SDA) Connects to external sensors and display screens, etc. Tests the power supply voltage of VDD3P3 (Pin3 and Pin4) and the input power voltage of TOUT (Pin6). However, these two functions cannot be used simultaneously. This interface is typically used in sensors. Communicates with the UART device. Downloading: U0TXD + U0RXD or GPIO2 + U0RXD UART0: TXD (U0TXD), UART RXD (U0RXD), IO15 (RTS), IO13 (CTS) UART1: IO2 (TXD) Espressif Communicating: (UART0): U0TXD, U0RXD, MTDO (U0RTS), MTCK (U0CTS) Debugging: UART1_TXD (GPIO2) can be used to print debugging information. By default, UART0 will output some printed information when you power on ESP8266EX. If this issue influences some specific applications, users can exchange the inner pins of UART when initializing ESP8266EX, that is, exchange U0TXD and U0RXD with U0RTS and U0CTS. Users can connect MTDO and MTCK to the serial port of the external MCU to realize the communication. Not Recommended For New Designs (NRND) #6/#18 2022.03 Submit Documentation Feedback 3. Functional Description # Interface Pin Functional Description I2S input: IO12 (I2SI_DATA) ; IO13 (I2SI_BCK ); I2S IO14 (I2SI_WS); Collects, processes and transmits audio data. I2S output: IO15 (I2SO_BCK ); IO3 (I2SO_DATA); IO2 (I2SO_WS ). Espressif Not Recommended For New Designs (NRND) #7/#18 2022.03 Submit Documentation Feedback 4. Electrical Characteristics # 4. Electrical Characteristics 📖 Note: Unless otherwise specified, measurements are based on VDD = 3.3 V, TA = 25 °C. 4.1. Electrical Characteristics Table 4-1. Electrical Characteristics Parameter Symbol Min Typ Max Unit Storage temperatue - –40 Normal 85 ℃ Operating temperature - –40 20 85 ℃ Maximum soldering temperature (Condition: IPC/JEDEC J-STD-020) - - - 260 ℃ Supply voltage VDD 2.7 3.3 3.6 V Input logic level low VIL –0.3 - 0.25 VDD V Input logic level high VIH 0.75 VDD - VDD + 0.3 V Output logic level low VOL - - 0.1 VDD V Output logic level high VOH 0.8 VDD - - V 4.2. Wi-Fi Radio Table 4-2. Wi-Fi Radio Characteristics Description Min Typ Max Unit Input frequency 2412 - 2484 MHz Input reflection -　 - –10 dB Output Power PA output power at 72.2 Mbps 13 14 15 dBm PA output power in 11b mode 19.5 20 20.5 dBm Sensitivity Espressif DSSS, 1 Mbps - –98 - dBm CCK, 11 Mbps - –91 - dBm Not Recommended For New Designs (NRND) #8/#18 2022.03 Submit Documentation Feedback 4. Electrical Characteristics # Description Min Typ Max Unit CCK, 11 Mbps - –91 - dBm 6 Mbps (1/2 BPSK) - –93 - dBm 54 Mbps (3/4 64-QAM) - –75 - dBm HT20, MCS7 (65 Mbps, 72.2 Mbps) - –72 - dBm Adjacent channel rejection OFDM, 6 Mbps - 37 - dB OFDM, 54 Mbps - 21 - dB HT20, MCS0 - 37 - dB HT20, MCS7 - 20 - dB 4.3. Power Consumption The following power consumption data were obtained from the tests with a 3.3 V power supply and a voltage stabilizer, in 25 °C ambient temperature. All data are based on 50% duty cycle in continuous transmission mode. Table 4-3. Power Consumption Espressif Modes Min Typ Max Unit Tx 802.11 b, CCK 11 Mbps, POUT = +17 dBm - 170 - mA Tx 802.11 g, OFDM 54 Mbps, POUT = +15 dBm - 140 - mA Tx 802.11 n, MCS7, POUT = +13 dBm - 120 - mA Rx 802.11 b, 1024 bytes packet length, -80 dBm - 50 - mA Rx 802.11 g, 1024 bytes packet length, -70 dBm - 56 - mA Rx 802.11 n, 1024 bytes packet length, -65 dBm - 56 - mA Modem-sleep① - 15 - mA Light-sleep② - 0.9 - mA Deep-sleep③ - 20 - μA Power Off - 0.5 - μA Not Recommended For New Designs (NRND) #9/#18 2022.03 Submit Documentation Feedback 4. Electrical Characteristics # 📖 Notes: ① Modem-sleep is used when such applications as PWM or I2S require the CPU to be working. In cases where Wi-Fi connectivity is maintained and data transmission is not required, the Wi-Fi Modem circuit can be shut down to save power, according to 802.11 standards (such as U-APSD). For example, in DTIM3, when ESP8266EX sleeps for 300 ms and wakes up for 3 ms to receive Beacon packages from AP, the overall average current consumption is about 15 mA. ② Light-sleep is used for applications whose CPU may be suspended, such as Wi-Fi switch. In cases where Wi-Fi connectivity is maintained and data transmission is not required, Wi-Fi Modem circuit and CPU can be shut down to save power, according to 802.11 standards (such as U-APSD). For example, in DTIM3, when ESP8266EX sleeps for 300 ms and wakes up for 3 ms to receive Beacon packages from AP, the overall average current consumption is about 0.9 mA. ③ Deep-sleep is for applications that do not require Wi-Fi connectivity and only transmit data over long time lags, e.g., a temperature sensor that measures temperature every 100 s. For example, when ESP8266EX sleeps for 300 s then wakes up to connect to AP (taking about 0.3 ~ 1 s), the overall average current consumption is far less than 1 mA. The current consumption of 20 μA was obtained at the voltage of 2.5 V. Temperature (℃) 4.4. Reflow Profile Peak Temp. 235 ~ 250℃ 250 Preheating zone 150 ~ 200℃ 60 ~ 120s 217 200 Reflow zone 217℃ 60 ~ 90s Cooling zone -1 ~ -5℃/s Soldering time > 30s Ramp-up zone 1 ~ 3℃/s 100 50 25 Time (sec.) 0 0 # 50 100 150 200 250 Ramp-up zone — Temp.: 217℃ 60 ~ 90s; Peak Temp.: 235 ~ 250℃ (