1 Module Overview 1.1 Features 1.2 Series Comparison 1.3 Applications 2 Block Diagram 3 Pin Definitions 3.1 Pin Layout 3.2 Pin Description 4 Boot Configurations 4.1 Chip Boot Mode Control 4.2 ROM Messages Printing Control 5 Peripherals 5.1 Peripheral Overview 5.2 Peripheral Description 5.2.1 Connectivity Interface 5.2.1.1 UART Controller 5.2.1.2 SPI Controller 5.2.1.3 I2C Controller 5.2.1.4 LED PWM Controller 5.2.2 Analog Signal Processing 5.2.2.1 SAR ADC 5.2.2.2 Temperature Sensor 6 Electrical Characteristics 6.1 Absolute Maximum Ratings 6.2 Recommended Operating Conditions 6.3 DC Characteristics (3.3 V, 25 °C) 6.4 Current Consumption Characteristics 6.4.1 Current Consumption in Active Mode 6.4.2 Current Consumption in Other Modes 7 RF Characteristics 7.1 Wi-Fi Radio 7.1.1 Wi-Fi RF Standards 7.1.2 Wi-Fi RF Transmitter (TX) Characteristics 7.1.3 Wi-Fi RF Receiver (RX) Characteristics 7.2 Bluetooth LE Radio 7.2.1 Bluetooth LE RF Transmitter (TX) Characteristics 7.2.2 Bluetooth LE RF Receiver (RX) Characteristics 8 Module Schematics 9 Peripheral Schematics 10 Physical Dimensions 10.1 Module Dimensions 10.2 Dimensions of External Antenna Connector 11 PCB Layout Recommendations 11.1 PCB Land Pattern 11.2 Module Placement for PCB Design 12 Product Handling 12.1 Storage Conditions 12.2 Electrostatic Discharge (ESD) 12.3 Reflow Profile 12.4 Ultrasonic Vibration Related Documentation and Resources Revision History ESP8684-WROOM-02C ESP8684-WROOM-02UC Datasheet Version 1.4 2.4 GHz Wi-Fi (802.11 b/g/n) and Bluetooth ® 5 module Built around ESP8684 series of SoC, RISC-V single-core microprocessor 2 MB/4 MB flash in chip package 14 GPIOs On-board PCB antenna or external antenna connector ESP8684-WROOM-02C ESP8684-WROOM-02UC www.espressif.com 1 Module Overview 1 Module Overview Note: Check the link or the QR code to make sure that you use the latest version of this document: https://www.espressif.com/sites/default/files/documentation/esp8684-wroom-02c_datasheet_en.pdf 1.1 Features CPU and On-Chip Memory • ESP8684H2X or ESP8684H4X embedded, 32-bit RISC-V single-core processor, up to 120 MHz • 576 KB ROM • 272 KB SRAM (16 KB for cache) • In-Package flash (see details in Table 1 and Table 2) • Access to flash accelerated by cache • Supports flash In-Circuit Programming (ICP) Wi-Fi • 802.11 b/g/n • Center frequency range of operating channel: 2412 ~ 2484 MHz • Supports 20 MHz bandwidth in 2.4 GHz band • 1T1R mode with data rate up to 72.2 Mbps • Wi-Fi Multimedia (WMM) • TX/RX A-MPDU, TX/RX A-MSDU • Immediate Block ACK • Fragmentation and defragmentation • Transmit opportunity (TXOP) • Automatic Beacon monitoring (hardware TSF) • 3 × virtual Wi-Fi interfaces • Simultaneous support for Infrastructure BSS in Station mode, SoftAP mode, Station + SoftAP mode, and promiscuous mode Note that when ESP8684 series scans in Station mode, the SoftAP channel will change along with the Station channel Bluetooth ® • Bluetooth LE: Bluetooth 5.3 certified • High power mode (20 dBm) • Speed: 125 kbps, 500 kbps, 1 Mbps, 2 Mbps • Advertising extensions • Multiple advertisement sets • Channel selection algorithm #2 • Internal co-existence mechanism between Wi-Fi and Bluetooth to share the same antenna Peripherals • Up to 14 GPIOs – 2 strapping GPIOs • GPIO, SPI, UART, I2C, LED PWM controller, general DMA controller, SAR ADC, temperature sensor, general-purpose timers, system timers, and watchdog timers Note: * Please refer to ESP8684 Series Datasheet for de- tailed information about the module peripherals. Integrated Components on Module • 26 MHz crystal oscillator Espressif Systems 2 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 1 Module Overview Antenna Options • On-board PCB antenna (ESP8684-WROOM-02C) • External antenna via a connector (ESP8684-WROOM-02UC) Operating Conditions • Operating voltage/Power supply: 3.0 ~ 3.6 V • Operating ambient temperature: –40 ~ 105 °C Certification • RF certification: See certificates • Green certification: RoHS/REACH Test • HTOL/HTSL/uHAST/TCT/ESD/Latch-up 1.2 Series Comparison ESP8684-WROOM-02C and ESP8684-WROOM-02UC are two generic Wi-Fi and Bluetooth LE modules. The rich set of peripherals and high performance make the modules an ideal choice for smart homes, industrial automation, health care, consumer electronics, etc. ESP8684-WROOM-02C comes with an on-board PCB antenna. ESP8684-WROOM-02UC comes with a connector for an external antenna. Both ESP8684-WROOM-02C and ESP8684-WROOM-02UC are available in two variants that integrate the ESP8684H2X and ESP8684H4X chip respectively. The series comparison for the two modules is as follows: Table 1: ESP8684-WROOM-02C (ANT) Series Comparison 1 Ambient Temp. 5 Size 6 Ordering Code In-Package flash 2,3 Chip Revision 4 (°C) (mm) ESP8684-WROOM-02C-H2X 2 MB v2.0 –40 ~105 18.0 × 20.0 ×3.2 ESP8684-WROOM-02C-H4X 4 MB 1 This table shares the same notes presented in Table 2 below. Table 2: ESP8684-WROOM-02UC (CONN) Series Comparison Ambient Temp. 5 Size 6 Ordering Code In-Package flash 2,3 Chip Revision 4 (°C) (mm) ESP8684-WROOM-02UC-H2X 2 MB v2.0 –40 ~105 18.0 ×14.3 ×3.2 ESP8684-WROOM-02UC-H4X 4 MB 2 The in-package flash supports: - More than 100,000 program/erase cycles - More than 20 years data retention time 3 By default, the SPI flash on the module operates at a maximum clock frequency of 60 MHz and does not support the auto suspend feature. If you need the flash auto suspend feature, please contact us. 4 Compared to previous chip versions, chip version v2.0 provides an additional 20 KB of SRAM and approximately 100 KB of flash memory (subject to actual application). 5 Ambient temperature specifies the recommended temperature range of the environment immediately outside the Espressif module. 6 For details, refer to Section 10.1 Module Dimensions. Espressif Systems 3 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 1 Module Overview The ESP8684H2X chip and the ESP8684H4X chip fall into the same category, namely ESP8684 chip series. ESP8684 series of chips have a 32-bit RISC-V single-core processor. They integrate a rich set of peripherals including GPIO, SPI, UART, I2C, LED PWM controller, general DMA controller, SAR ADC, temperature sensor, general-purpose timers, system timers, and watchdog timers. Note: For more information on ESP8684, please refer to ESP8684 Series Datasheet. 1.3 Applications • Smart Home • Industrial Automation • Health Care • Consumer Electronics • Smart Agriculture • POS Machines • Service Robot • Generic Low-power IoT Sensor Hubs • Generic Low-power IoT Data Loggers Espressif Systems 4 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 Contents Contents 1 Module Overview 2 1.1 Features 2 1.2 Series Comparison 3 1.3 Applications 4 2 Block Diagram 9 3 Pin Definitions 10 3.1 Pin Layout 10 3.2 Pin Description 10 4 Boot Configurations 12 4.1 Chip Boot Mode Control 13 4.2 ROM Messages Printing Control 13 5 Peripherals 15 5.1 Peripheral Overview 15 5.2 Peripheral Description 15 5.2.1 Connectivity Interface 15 5.2.1.1 UART Controller 15 5.2.1.2 SPI Controller 16 5.2.1.3 I2C Controller 17 5.2.1.4 LED PWM Controller 17 5.2.2 Analog Signal Processing 17 5.2.2.1 SAR ADC 18 5.2.2.2 Temperature Sensor 18 6 Electrical Characteristics 19 6.1 Absolute Maximum Ratings 19 6.2 Recommended Operating Conditions 19 6.3 DC Characteristics (3.3 V, 25 °C) 19 6.4 Current Consumption Characteristics 20 6.4.1 Current Consumption in Active Mode 20 6.4.2 Current Consumption in Other Modes 20 7 RF Characteristics 22 7.1 Wi-Fi Radio 22 7.1.1 Wi-Fi RF Standards 22 7.1.2 Wi-Fi RF Transmitter (TX) Characteristics 22 7.1.3 Wi-Fi RF Receiver (RX) Characteristics 23 7.2 Bluetooth LE Radio 24 7.2.1 Bluetooth LE RF Transmitter (TX) Characteristics 24 7.2.2 Bluetooth LE RF Receiver (RX) Characteristics 25 Espressif Systems 5 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 Contents 8 Module Schematics 28 9 Peripheral Schematics 30 10 Physical Dimensions 31 10.1 Module Dimensions 31 10.2 Dimensions of External Antenna Connector 32 11 PCB Layout Recommendations 34 11.1 PCB Land Pattern 34 11.2 Module Placement for PCB Design 35 12 Product Handling 36 12.1 Storage Conditions 36 12.2 Electrostatic Discharge (ESD) 36 12.3 Reflow Profile 36 12.4 Ultrasonic Vibration 37 Related Documentation and Resources 38 Revision History 39 Espressif Systems 6 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 List of Tables List of Tables 1 ESP8684-WROOM-02C (ANT) Series Comparison 1 3 2 ESP8684-WROOM-02UC (CONN) Series Comparison 3 3 Pin Definitions 11 4 Default Configuration of Strapping Pins 12 5 Description of Timing Parameters for the Strapping Pins 12 6 Chip Boot Mode Control 13 7 UART0 ROM Message Printing Control 14 8 Absolute Maximum Ratings 19 9 Recommended Operating Conditions 19 10 DC Characteristics (3.3 V, 25 °C) 19 11 Current Consumption Depending on RF Modes 20 12 Current Consumption in Modem-sleep Mode 20 13 Current Consumption in Low-Power Modes 20 14 Wi-Fi RF Standards 22 15 TX Power with Spectral Mask and EVM Meeting 802.11 Standards 22 16 TX EVM Test 23 17 RX Sensitivity 23 18 Maximum RX Level 23 19 RX Adjacent Channel Rejection 24 20 Transmitter General Characteristics 24 21 Transmitter Characteristics - Bluetooth LE 1 Mbps 24 22 Transmitter Characteristics - Bluetooth LE 2 Mbps 25 23 Transmitter Characteristics - Bluetooth LE 125 kbps 25 24 Transmitter Characteristics - Bluetooth LE 500 kbps 25 25 Receiver Characteristics - Bluetooth LE 1 Mbps 26 26 Receiver Characteristics - Bluetooth LE 2 Mbps 26 27 Receiver Characteristics - Bluetooth LE 125 kbps 27 28 Receiver Characteristics - Bluetooth LE 500 kbps 27 Espressif Systems 7 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 List of Figures List of Figures 1 ESP8684-WROOM-02C Block Diagram 9 2 ESP8684-WROOM-02UC Block Diagram 9 3 Pin Layout (Top View) 10 4 Visualization of Timing Parameters for the Strapping Pins 13 5 ESP8684-WROOM-02C Schematics 28 6 ESP8684-WROOM-02UC Schematics 29 7 Peripheral Schematics 30 8 ESP8684-WROOM-02C Physical Dimensions 31 9 ESP8684-WROOM-02UC Physical Dimensions 31 10 Dimensions of External Antenna Connector 32 11 ESP8684-WROOM-02C Recommended PCB Land Pattern 34 12 ESP8684-WROOM-02UC Recommended PCB Land Pattern 35 13 Reflow Profile 36 Espressif Systems 8 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 2 Block Diagram 2 Block Diagram SPI Flash ESP8684 RF Matching 26 MHz Crystal 3V3 EN GPIOs Antenna GND SPI Flash ESP8684 26 MHz Crystal 3V3 EN GPIOs GND RF Matching Antenna Figure 1: ESP8684-WROOM-02C Block Diagram SPI Flash ESP8684 RF Matching 26 MHz Crystal 3V3 EN GPIOs Antenna GND SPI Flash ESP8684 26 MHz Crystal 3V3 EN GPIOs GND RF Matching Antenna Figure 2: ESP8684-WROOM-02UC Block Diagram Espressif Systems 9 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 3 Pin Definitions 3 Pin Definitions 3.1 Pin Layout The pin diagram below shows the approximate location of pins on the module. For the actual diagram drawn to scale, please refer to Figure 10.1 Module Dimensions. 1 2 3 4 5 6 7 8 9 3V3 EN IO4 IO5 IO6 IO7 IO8 IO9 GND 18 17 16 15 14 13 12 11 10 IO0 IO1 IO2 IO3 IO18 NC TXD RXD IO10 Keepout Zone 19:GND GND A Figure 3: Pin Layout (Top View) Note A: The zone marked with dotted lines is the antenna keepout zone. The pin diagram is applicable to ESP8684-WROOM-02C and ESP8684-WROOM-02UC, but the latter has no antenna keepout zone. To learn more about the keepout zone for module’s antenna on the base board, please refer to ESP8684 Hardware Design Guidelines > Section Positioning a Module on a Base Board. 3.2 Pin Description ESP8684-WROOM-02UC and ESP8684-WROOM-02C both have 19 pins, respectively. See pin definitions in Table 3 Pin Description. For peripheral pin configurations, please refer to 5.2 Peripheral Description. Espressif Systems 10 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 3 Pin Definitions Table 3: Pin Definitions Name No. Type 1 Function 3V3 1 P Power supply EN 2 I High: on, enables the chip. Low: off, the chip powers off. Note: Do not leave the CHIP_EN pin floating. IO4 3 I/O/T GPIO4, ADC1_CH4, FSPIHD, MTMS IO5 4 I/O/T GPIO5, FSPIWP, MTDI IO6 5 I/O/T GPIO6, FSPICLK, MTCK IO7 6 I/O/T GPIO7, FSPID, MTDO IO8 7 I/O/T GPIO8 This pin is internally pulled high. IO9 8 I/O/T GPIO9 GND 9 P Ground IO10 10 I/O/T GPIO10, FSPICS0 RXD 11 I/O/T GPIO19, U0RXD TXD 12 I/O/T GPIO20, U0TXD NC 13 — NC IO18 14 I/O/T GPIO18 IO3 15 I/O/T GPIO3, ADC1_CH3 IO2 16 I/O/T GPIO2, ADC1_CH2, FSPIQ IO1 17 I/O/T GPIO1, ADC1_CH1 IO0 18 I/O/T GPIO0, ADC1_CH0 GND 19 P Ground 1 P: power supply; I: input; O: output; T: high impedance. Note: IO0, IO1, IO3, IO5/MTDI pins have low-level glitches during chip power up. See details in section General Purpose Input / Output Interface (GPIO) of ESP8684 Series Datasheet. Espressif Systems 11 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 4 Boot Configurations 4 Boot Configurations Note: The content below is excerpted from ESP8684 Series Datasheet > Section Boot Configurations. For the strapping pin mapping between the chip and modules, please refer to Chapter 8 Module Schematics. The module allows for configuring the following boot parameters through strapping pins and eFuse parameters at power-up or a hardware reset, without microcontroller interaction. • Chip boot mode – Strapping pin: GPIO8 and GPIO9 • ROM message printing – Strapping pin: GPIO8 – eFuse parameter: EFUSE_UART_PRINT_CONTROL The default values of all the above eFuse parameters are 0, which means that they are not burnt. Given that eFuse is one-time programmable, once programmed to 1, it can never be reverted to 0. For how to program eFuse parameters, please refer to ESP8684 Technical Reference Manual > Chapter eFuse Controller. The default values of the strapping pins, namely the logic levels, are determined by pins’ internal weak pull-up/pull-down resistors at reset if the pins are not connected to any circuit, or connected to an external high-impedance circuit. Table 4: Default Configuration of Strapping Pins Strapping Pin Default Configuration Bit Value GPIO8 N/A - GPIO9 Internal weak pull-up 1 To change the bit values, the strapping pins should be connected to external pull-down/pull-up resistances. If the ESP8684 is used as a device by a host MCU, the strapping pin voltage levels can also be controlled by the host MCU. All strapping pins have latches. At system reset, the latches sample the bit values of their respective strapping pins and store them until the chip is powered down or shut down. The states of latches cannot be changed in any other way. It makes the strapping pin values available during the entire chip operation, and the pins are freed up to be used as regular IO pins after reset. The timing of signals connected to the strapping pins should adhere to the setup time and hold time specifications in Table 5 and Figure 4. Table 5: Description of Timing Parameters for the Strapping Pins Parameter Description Min (ms) t 0 Setup time before CHIP_EN goes from low to high 0 t 1 Hold time after CHIP_EN goes high 3 Espressif Systems 12 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 4 Boot Configurations CHIP_EN t 1 t 0 Strapping pin V IL_nRST V IH Figure 4: Visualization of Timing Parameters for the Strapping Pins 4.1 Chip Boot Mode Control GPIO8 and GPIO9 control the boot mode after the reset is released. See Table 6 Chip Boot Mode Control. Table 6: Chip Boot Mode Control Boot Mode GPIO9 GPIO8 SPI boot mode 1 x 2 Joint download boot mode 3 0 1 1 Bold marks the default value and configuration. 2 Values that have no effect on the result and can therefore be ignored. 3 Joint Download Boot mode supports UART Download Boot. In addition to SPI Boot and Joint Download Boot modes, ESP8684 also supports SPI Download Boot mode. For details, please see ESP8684 Technical Reference Manual > Chapter Chip Boot Control. 4.2 ROM Messages Printing Control EFUSE_UART_PRINT_CONTROL and GPIO8 control ROM messages printing to UART0 as shown in Table 7 UART0 ROM Message Printing Control. Espressif Systems 13 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 4 Boot Configurations Table 7: UART0 ROM Message Printing Control UART0 ROM Code Printing eFuse 1 GPIO8 Enabled 0 Ignored 1 0 2 1 Disabled 1 1 2 0 3 Ignored 1 EFUSE_UART_PRINT_CONTROL Espressif Systems 14 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 5 Peripherals 5 Peripherals 5.1 Peripheral Overview ESP8684 integrates a rich set of peripherals including GPIO, SPI, UART, I2C, LED PWM controller, general DMA controller, SAR ADC, temperature sensor, general-purpose timers, system timers, and watchdog timers. To learn more about on-chip components, please refer to ESP8684 Series Datasheet > Section Functional Description. Note: The content below is sourced from ESP8684 Series Datasheet > Section Peripherals. Some information may not be ap- plicable to ESP8684-WROOM-02C and ESP8684-WROOM-02UC as not all the IO signals are exposed on the module. To learn more about peripheral signals, please refer to ESP8684 Technical Reference Manual > Section Peripheral Signal List. 5.2 Peripheral Description This section describes the chip’s peripheral capabilities, covering connectivity interfaces and on-chip sensors that extend its functionality. 5.2.1 Connectivity Interface This subsection describes the connectivity interfaces on the chip that enable communication and interaction with external devices and networks. 5.2.1.1 UART Controller The UART Controller in the ESP8684 chip facilitates the transmission and reception of asynchronous serial data between the chip and external UART devices. It supports two UART interfaces. Feature List • Full-duplex asynchronous communication • Configurable baud rate, up to 2.5 Mbaud • Automatic baud rate detection of input signals • Data frame format: – a START bit – data bits, ranging from 5 ~ 8 – a parity bit – stop bits, whose length can be 1, 1.5, or 2 bits • Special character AT_CMD detection • Supported protocols: RS485, IrDA Espressif Systems 15 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 5 Peripherals • UART as wake-up source • Software and hardware flow control • Three clock sources that can be divided: – 40 MHz PLL_F40M_CLK – internal fast RC oscillator RC_FAST_CLK – external crystal clock XTAL_CLK • 512 x 8-bit RAM shared by TX FIFOs and RX FIFOs of the two UART controllers Pin Assignment For UART, the pins used can be chosen from any GPIOs via the GPIO Matrix. For more information about the pin assignment, see ESP8684 Series Datasheet > Section IO Pins and ESP8684 Technical Reference Manual > Chapter IO MUX and GPIO Matrix. 5.2.1.2 SPI Controller ESP8684 series features three SPI interfaces (SPI0, SPI1, and SPI2). SPI0 and SPI1 can be configured to operate in SPI memory mode and SPI2 can be configured to operate in general-purpose SPI mode. SPI0 and SPI1 are reserved for system use, and only SPI2 is available for users. Features of SPI0 and SPI1 • Data is transferred in bytes • Up to four-line STR reads and writes are supported • The clock frequency is configurable to a maximum of 60 MHz in STR mode Features of SPI2 General-purpose SPI (GP-SPI) • It can operate in master and slave modes • It supports two-line full-duplex communication and single-/two-/four-line half-duplex communication in both master and slave modes • The host’s clock frequency of SPI2 is configurable. The clock frequency is 40 MHz at most • Data is transferred in bytes • The clock polarity (CPOL) and phase (CPHA) are also configurable • The SPI2 interface can connect to GDMA Pin Assignment For SPI2, the pins used can be chosen from any GPIOs via the GPIO Matrix. For more information about the pin assignment, see ESP8684 Series Datasheet > Section IO Pins and ESP8684 Technical Reference Manual > Chapter IO MUX and GPIO Matrix. Espressif Systems 16 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 5 Peripherals 5.2.1.3 I2C Controller The I2C Controller supports communication between the master and slave devices using the I2C bus. Feature List • one I2C controller operating in master mode • Standard mode (100 Kbit/s) and fast mode (400 Kbit/s) • Up to 800 Kbit/s (constrained by SCL and SDA pull-up strength) • Support for 7-bit and 10-bit addressing, as well as dual address mode • 7-bit broadcast address Pin Assignment For I2C, the pins used can be chosen from any GPIOs via the GPIO Matrix. For more information about the pin assignment, see ESP8684 Series Datasheet > Section IO Pins and ESP8684 Technical Reference Manual > Chapter IO MUX and GPIO Matrix. 5.2.1.4 LED PWM Controller The LED PWM Controller (LEDC) is designed to generate PWM signals for LED control. Feature List • Six independent PWM generators • Maximum PWM duty cycle resolution of 14 bits • Four independent timers with 14-bit counters, configurable fractional clock dividers and counter overflow values • Adjustable phase of PWM signal output • PWM duty cycle dithering • Automatic duty cycle fading • PWM signal output in low-power mode (Light-sleep mode) Pin Assignment The pins for the LED PWM Controller can be chosen from any GPIOs via the GPIO Matrix. For more information about the pin assignment, see ESP8684 Series Datasheet > Section IO Pins and ESP8684 Technical Reference Manual > Chapter IO MUX and GPIO Matrix. 5.2.2 Analog Signal Processing This subsection describes components on the chip that sense and process real-world data. Espressif Systems 17 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 5 Peripherals 5.2.2.1 SAR ADC ESP8684 integrates a Successive Approximation Analog-to-Digital Converter (SAR ADC) to convert analog signals into digital representations. Feature List • 12-bit sampling resolution • Analog voltage sampling from up to five pins • One DIG ADC controller – Provides separate control modules for one-time sampling and multi-channel scanning – Supports one-time sampling and multi-channel scanning working simultaneously – User-defined scanning sequence in multi-channel scanning mode – Provides two filters with configurable filter coefficient – Supports threshold monitoring Pin Assignment The pins for the SAR ADC are multiplexed with GPIO0 ~ GPIO4, JTAG. For more information about the pin assignment, see ESP8684 Series Datasheet > Section IO Pins and ESP8684 Technical Reference Manual > Chapter IO MUX and GPIO Matrix. 5.2.2.2 Temperature Sensor The Temperature Sensor in the ESP8684 chip allows for real-time monitoring of temperature changes inside the chip. Feature List • Measurement range: –40 °C ~ 125 °C • Software triggering, wherein the data can be read continuously once triggered • Configurable temperature offset based on the environment to improve the accuracy • Adjustable measurement range Espressif Systems 18 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 6 Electrical Characteristics 6 Electrical Characteristics 6.1 Absolute Maximum Ratings Stresses above those listed in Table 8 Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under Table 9 Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Table 8: Absolute Maximum Ratings Symbol Parameter Min Max Unit VDD33 Power supply voltage –0.3 3.6 V T ST OR E Storage temperature –40 105 °C 6.2 Recommended Operating Conditions Table 9: 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 A Operating ambient temperature –40 — 105 °C 6.3 DC Characteristics (3.3 V, 25 °C) Table 10: 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 1 — VDD 1 + 0.3 V V IL Low-level input voltage –0.3 — 0.25 × VDD 1 V I IH High-level input current — — 50 nA I IL Low-level input current — — 50 nA V OH 2 High-level output voltage 0.8 × VDD 1 — — V V OL 2 Low-level output voltage — — 0.1 × VDD 1 V I OH High-level source current (VDD 1 = 3.3 V, V OH >= 2.64 V, PAD_DRIVER = 3) — 40 — mA I OL Low-level sink current (VDD 1 = 3.3 V, V OL = 0.495 V, PAD_DRIVER = 3) — 28 — mA R P U Pull-up resistor — 45 — kΩ R P D Pull-down resistor — 45 — kΩ V IH_nRST Chip reset release voltage 0.75 × VDD 1 — VDD 1 + 0.3 V V IL_nRST Chip reset voltage –0.3 — 0.25 × VDD 1 V Espressif Systems 19 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 6 Electrical Characteristics 1 VDD is the I/O voltage for a particular power domain of pins. 2 V OH and V OL are measured using high-impedance load. 6.4 Current Consumption Characteristics 6.4.1 Current Consumption in Active Mode The current consumption measurements are taken with a 3.3 V supply at 25 °C ambient temperature. TX current consumption is rated at a 100% duty cycle. RX current consumption is rated when the peripherals are disabled and the CPU idle. Table 11: Current Consumption Depending on RF Modes Work mode Description Peak (mA) Active (RF working) TX 802.11b, 1 Mbps, @21 dBm 310 802.11g, 54 Mbps, @19 dBm 260 802.11n, HT20, MCS 7, @18 dBm 250 RX 802.11b/g/n, HT20 65 Note: The content below is excerpted from Section Power Consumption in Other Modes in ESP8684 Series Datasheet. 6.4.2 Current Consumption in Other Modes Table 12: Current Consumption in Modem-sleep Mode Typ Mode CPU Frequency (MHz) Description All Peripherals Clocks Disabled (mA) All Peripherals Clocks Enabled (mA) 1 Modem-sleep 2,3 80 CPU is running 12.1 13.0 WFI (Wait-for-Interrupt) 9.4 10.3 120 CPU is running 14.7 15.6 WFI (Wait-for-Interrupt) 10.7 11.5 1 In practice, the current consumption might be different depending on which peripherals are enabled. 2 In Modem-sleep mode, Wi-Fi is clock gated. 3 In Modem-sleep mode, the consumption might be higher when accessing flash. For a flash rated at 80 Mbit/s, in SPI 2-line mode the consumption is 10 mA. Table 13: Current Consumption in Low-Power Modes Work mode Description Typ Unit Light-sleep — 140 µA Deep-sleep Only RTC timer is powered on 5 µA Espressif Systems 20 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 6 Electrical Characteristics Power off CHIP_EN is set to low level, and the chip is powered off 1 µA Espressif Systems 21 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 7 RF Characteristics 7 RF Characteristics This section contains tables with RF characteristics of the Espressif product. The RF data is measured at the antenna port, where RF cable is connected, including the front-end loss. The external antennas used for the tests on the modules with external antenna connectors have an impedance of 50 Ω.Devices should operate in the center frequency range allocated by regional regulatory authorities. The target center frequency range and the target transmit power are configurable by software. See ESP RF Test Tool and Test Guide for instructions. Unless otherwise stated, the RF tests are conducted with a 3.3 V (±5%) supply at 25 ºC ambient temperature. 7.1 Wi-Fi Radio 7.1.1 Wi-Fi RF Standards Table 14: Wi-Fi RF Standards Name Description Center frequency range of operating channel 2412 ~ 2484 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: MCS 0-7, 72.2 Mbps (Max) Antenna type PCB antenna 7.1.2 Wi-Fi RF Transmitter (TX) Characteristics Target TX power is configurable based on device or certification requirements. The default characteristics are provided in Table 15. Table 15: TX Power with Spectral Mask and EVM Meeting 802.11 Standards Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 1 Mbps — 21 — 802.11b, 11 Mbps — 21 — 802.11g, 6 Mbps — 21 — 802.11g, 54 Mbps — 19 — 802.11n, HT20, MCS 0 — 19 — 802.11n, HT20, MCS 7 — 18 — Espressif Systems 22 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 7 RF Characteristics Table 16: TX EVM Test Min Typ SL 1 Rate (dB) (dB) (dB) 802.11b, 1 Mbps, @21 dBm — –24 –10 802.11b, 11 Mbps, @21 dBm — –24 –10 802.11g, 6 Mbps, @21 dBm — –23 –5 802.11g, 54 Mbps, @19 dBm — –30 –25 802.11n, HT20, MCS 0, @20 dBm — –27 –5 802.11n, HT20, MCS 7, @18 dBm — –31 –27 1 SL stands for standard limit value. 7.1.3 Wi-Fi RF Receiver (RX) Characteristics Table 17: RX Sensitivity Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 1 Mbps — –99.0 — 802.11b, 2 Mbps — –96.5 — 802.11b, 5.5 Mbps — –94.0 — 802.11b, 11 Mbps — –90.0 — 802.11g, 6 Mbps — –94.0 — 802.11g, 9 Mbps — –92.0 — 802.11g, 12 Mbps — –91.0 — 802.11g, 18 Mbps — –89.0 — 802.11g, 24 Mbps — –86.0 — 802.11g, 36 Mbps — –83.0 — 802.11g, 48 Mbps — –78.5 — 802.11g, 54 Mbps — –77.0 — 802.11n, HT20, MCS 0 — –92.5 — 802.11n, HT20, MCS 1 — –90.5 — 802.11n, HT20, MCS 2 — –87.5 — 802.11n, HT20, MCS 3 — –84.5 — 802.11n, HT20, MCS 4 — –81.5 — 802.11n, HT20, MCS 5 — –77.5 — 802.11n, HT20, MCS 6 — –75.5 — 802.11n, HT20, MCS 7 — –74.0 — Table 18: Maximum RX Level Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 1 Mbps — 5 — Cont’d on next page Espressif Systems 23 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 7 RF Characteristics Table 18 – cont’d from previous page Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 11 Mbps — 5 — 802.11g, 6 Mbps — 5 — 802.11g, 54 Mbps — 0 — 802.11n, HT20, MCS 0 — 5 — 802.11n, HT20, MCS 7 — 0 — Table 19: RX Adjacent Channel Rejection Min Typ Max Rate (dB) (dB) (dB) 802.11b, 1 Mbps — 35 — 802.11b, 11 Mbps — 35 — 802.11g, 6 Mbps — 31 — 802.11g, 54 Mbps — 20 — 802.11n, HT20, MCS 0 — 16 — 802.11n, HT20, MCS 7 — 25 — 7.2 Bluetooth LE Radio 7.2.1 Bluetooth LE RF Transmitter (TX) Characteristics Table 20: Transmitter General Characteristics Parameter Min Typ Max Unit RF transmit power — 3 — dBm Gain control step — 3 — dB RF power control range –24 — 20 dBm Table 21: Transmitter Characteristics - Bluetooth LE 1 Mbps Parameter Description Min Typ Max Unit In-band emissions F = F0 ± 2 MHz — –32.0 — dBm F = F0 ± 3 MHz — –38.0 — dBm F = F0 ± > 3 MHz — –41.0 — dBm Modulation characteristics ∆ f1 avg — 249.0 — kHz ∆ f2 max — 246.0 — kHz ∆ f2 avg /∆ f1 avg — 1.1 — — Carrier frequency offset Max |f n | n=0, 1, 2, ..k — 2.0 — kHz Carrier frequency drift Max |f 0 − f n | n=2, 3, 4, ..k — 1.0 — kHz Max |f 0 − f 1 | — 0.5 — kHz Max |f n − f n−5 | n=6, 7, 8, ..k — 1.0 — kHz Espressif Systems 24 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 7 RF Characteristics Table 22: Transmitter Characteristics - Bluetooth LE 2 Mbps Parameter Description Min Typ Max Unit In-band emissions F = F0 ± 4 MHz — –40.0 — dBm F = F0 ± 5 MHz — –43.0 — dBm F = F0 ± > 5 MHz — –44.0 — dBm Modulation characteristics ∆ f1 avg — 498.0 — kHz ∆ f2 max — 589.0 — kHz ∆ f2 avg /∆ f1 avg — 1.2 — — Carrier frequency offset Max |f n | n=0, 1, 2, ..k — 1.0 — kHz Carrier frequency drift Max |f 0 − f n | n=2, 3, 4, ..k — 3.0 — kHz Max |f 0 − f 1 | — 2.4 — kHz Max |f n − f n−5 | n=6, 7, 8, ..k — 1.2 — kHz Table 23: Transmitter Characteristics - Bluetooth LE 125 kbps Parameter Description Min Typ Max Unit In-band emissions F = F0 ± 2 MHz — –32.0 — dBm F = F0 ± 3 MHz — –38.0 — dBm F = F0 ± > 3 MHz — –41.0 — dBm Modulation characteristics ∆ f1 avg — 248.0 — kHz ∆ f1 max — 224.0 — kHz Carrier frequency offset Max |f n | n =0 , 1 , 2 , ..k — 0.5 — kHz Carrier frequency drift Max |f 0 − f n | n=1, 2, 3, ..k — 0.7 — kHz Max |f 0 − f 3 | — 0.2 — kHz Max |f n − f n−3 | n=7, 8, 9, ..k — 0.7 — kHz Table 24: Transmitter Characteristics - Bluetooth LE 500 kbps Parameter Description Min Typ Max Unit In-band emissions F = F0 ± 2 MHz — –32.0 — dBm F = F0 ± 3 MHz — –38.0 — dBm F = F0 ± > 3 MHz — –41.0 — dBm Modulation characteristics ∆ f2 avg — 273.0 — kHz ∆ f2 max — 243.0 — kHz Carrier frequency offset Max |f n | n=0, 1, 2, ..k — 0.5 — kHz Carrier frequency drift Max |f 0 − f n | n=1, 2, 3, ..k — 0.7 — kHz Max |f 0 − f 3 | — 0.7 — kHz Max |f n − f n−3 | n=7, 8, 9, ..k — 0.2 — kHz 7.2.2 Bluetooth LE RF Receiver (RX) Characteristics Espressif Systems 25 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 7 RF Characteristics Table 25: Receiver Characteristics - Bluetooth LE 1 Mbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –98 — dBm Maximum received signal @30.8% PER — — 8 — dBm Co-channel C/I — — 8 — dB Adjacent channel selectivity C/I F = F0 + 1 MHz — –1 — dB F = F0 – 1 MHz — –3 — dB F = F0 + 2 MHz — –26 — dB F = F0 – 2 MHz — –28 — dB F ≥ F0 + 3 MHz (1) — — — dB F ≤ F0 – 3 MHz — –31 — dB Image frequency — — –33 — dB Adjacent channel to image frequency F = F image + 1 MHz — –32 — dB F = F image – 1 MHz — –34 — dB Out-of-band blocking performance 30 MHz ~ 2000 MHz — –23 — dBm 2003 MHz ~ 2399 MHz — –30 — dBm 2484 MHz ~ 2997 MHz — –10 — dBm 3000 MHz ~ 12.75 GHz — –17 — dBm Intermodulation — — –31 — dBm 1 Refer to the value of adjacent channel to image frequency when F = F image – 1 MHz. Table 26: Receiver Characteristics - Bluetooth LE 2 Mbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –95 — dBm Maximum received signal @30.8% PER — — 8 — dBm Co-channel C/I F = F0 MHz — 9 — dB Adjacent channel selectivity C/I F = F0 + 2 MHz — –11 — dB F = F0 – 2 MHz — –7 — dB F = F0 + 4 MHz (1) — — — dB F = F0 – 4 MHz — –30 — dB F ≥ F0 + 6 MHz — –35 — dB F ≤ F0 – 6 MHz — –29 — dB Image frequency — — –35 — dB Adjacent channel to image frequency F = F image + 2 MHz — –35 — dB F = F image – 2 MHz (2) — — — dB Out-of-band blocking performance 30 MHz ~ 2000 MHz — –30 — dBm 2003 MHz ~ 2399 MHz — –34 — dBm 2484 MHz ~ 2997 MHz — –19 — dBm 3000 MHz ~ 12.75 GHz — –28 — dBm Intermodulation — — –33 — dBm 1 Refer to the value of Image frequency. 2 Refer to the value of Adjacent channel selectivity C/I when F = F0 + 2 MHz. Espressif Systems 26 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 7 RF Characteristics Table 27: Receiver Characteristics - Bluetooth LE 125 kbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –106 — dBm Maximum received signal @30.8% PER — — 8 — dBm Co-channel C/I F = F0 MHz — 3 — dB Adjacent channel selectivity C/I F = F0 + 1 MHz — –7 — dB F = F0 – 1 MHz — –5 — dB F = F0 + 2 MHz — -35 — dB F = F0 – 2 MHz — –34 — dB F ≥ F0 + 3 MHz (1) — — — dB F ≤ F0 – 3 MHz — –37 — dB Image frequency — — –41 — dB Adjacent channel to image frequency F = F image + 1 MHz — –43 — dB F = F image – 1 MHz — –38 — dB 1 Refer to the value of Adjacent channel to image frequency when F = F image – 1 MHz. Table 28: Receiver Characteristics - Bluetooth LE 500 kbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –102 — dBm Maximum received signal @30.8% PER — — 8 — dBm Co-channel C/I F = F0 MHz — 4 — dB Adjacent channel selectivity C/I F = F0 + 1 MHz — –6 — dB F = F0 – 1 MHz — –5 — dB F = F0 + 2 MHz — –29 — dB F = F0 – 2 MHz — –32 — dB F ≥ F0 + 3 MHz (1) — — — dB F ≤ F0 – 3 MHz — –36 — dB Image frequency — — –34 — dB Adjacent channel to image frequency F = F image + 1 MHz — –37 — dB F = F image – 1 MHz — –31 — dB 1 Refer to the value of Adjacent channel to image frequency when F = F image – 1 MHz. Espressif Systems 27 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 8 Module Schematics 8 Module Schematics This is the reference design of the module. GPIO3 CHIP_EN GPIO4 GPIO5 GPIO6 GPIO9 GPIO8 GPIO7 LNA_INRF_ANT U0TXD U0RXD GPIO2 GPIO0 GPIO1 GPIO10 GPIO18 GPIO10 U0RXD U0TXD GPIO18 GPIO3 GPIO2 GPIO1 GPIO0 GPIO9 GPIO8 GPIO7 GPIO6 GPIO5 GPIO4 CHIP_EN VDD33 GND GND GND GND GNDGND GND VDD33 GND GND GND GND GND GND GND GND VDD33 VDD33 VDD33 GND VDD33 GND GND The values of C8, L2 and C9 vary with the actual PCB board. The values of C1 and C2 vary with the selection of the crystal. The value of R1 varies with the actual PCB board. NC: No component. ESP8684 Core ESP8684-WROOM-02C(pin-out) C5 10uF R2 499(1%) C8 TBD U3 ESP8684-WROOM-02C 3V3 1 EN 2 IO4 3 IO5 4 IO6 5 IO7 6 IO8 7 IO9 8 GND 9 IO0 18 IO1 17 IO2 16 IO3 15 IO18 14 NC 13 TXD0 12 RXD0 11 IO10 10 EPAD 19 L2 TBD U2 ESP8684 ANT 1 VDDA3P3 2 VDDA3P3 3 GPIO0 4 GPIO1 5 GPIO2 6 CHIP_EN 7 MTMS 9 MTDI 10 VDD3P3_RTC 11 MTCK 12 MTDO 13 GPIO8 14 GPIO9 15 GPIO10 16 VDD3P3_CPU 17 U0RXD 19 U0TXD 20 XTAL_N 22 XTAL_P 23 GND 25 GPIO3 8 VDDA 24 VDDA 21 GPIO18 18 C9 TBD C7 0.1uF R9 10K L1 2.0nH(0.1nH) D1 ESD C4 10nF C12 0.1uF C1 TBD C2 TBD C10 0.1uF C3 1uF R1 TBD ANT1 PCB_ANT 1 2 C6 0.1uF U1 26MHz(±10ppm) XIN 1 GND 2 XOUT 3 GND 4 Figure 5: ESP8684-WROOM-02C Schematics Espressif Systems 28 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 8 Module Schematics 5 5 4 4 3 3 2 2 1 1 D D C C B B A A The values of C8, L2 and C9 vary with the actual PCB board. The values of C1 and C2 vary with the selection of the crystal. The value of R1 varies with the actual PCB board. NC: No component. ESP8684 Core ESP8684-WROOM-02UC(pin-out) VDD33 GND GND GND GND GNDGND VDD33 GND GND GND GND GND GND GND GND VDD33 VDD33 VDD33 GND VDD33 GND GND GND Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP8684-WROOM-02UC> 1.0 ESP8684-WROOM-02UC A4 2 2Thursday, September 15, 2022 Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP8684-WROOM-02UC> 1.0 ESP8684-WROOM-02UC A4 2 2Thursday, September 15, 2022 Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP8684-WROOM-02UC> 1.0 ESP8684-WROOM-02UC A4 2 2Thursday, September 15, 2022 C5 10uF R2 499(1%) C8 TBD U3 ESP8684-WROOM-02UC 3V3 1 EN 2 IO4 3 IO5 4 IO6 5 IO7 6 IO8 7 IO9 8 GND 9 IO0 18 IO1 17 IO2 16 IO3 15 IO18 14 NC 13 TXD0 12 RXD0 11 IO10 10 EPAD 19 L2 TBD ANT1 CONN 1 2 3 C9 TBD C7 0.1uF(NC) U2 ESP8684 ANT 1 VDDA3P3 2 VDDA3P3 3 GPIO0 4 GPIO1 5 GPIO2 6 CHIP_EN 7 MTMS 9 MTDI 10 VDD3P3_RTC 11 MTCK 12 MTDO 13 GPIO8 14 GPIO9 15 GPIO10 16 VDD3P3_CPU 17 U0RXD 19 U0TXD 20 XTAL_N 22 XTAL_P 23 GND 25 GPIO3 8 VDDA 24 VDDA 21 GPIO18 18 R9 10K L1 2.0nH D1 ESD C4 10nF C12 0.1uF C1 TBD C2 TBD C10 0.1uF C3 1uF R1 TBD C6 0.1uF U1 26MHz(±10ppm) XIN 1 GND 2 XOUT 3 GND 4 GPIO3 CHIP_EN GPIO4 GPIO5 GPIO6 GPIO9 GPIO8 GPIO7 LNA_INRF_ANT U0TXD U0RXD GPIO2 GPIO0 GPIO1 GPIO10 GPIO18 GPIO10 U0RXD U0TXD GPIO18 GPIO3 GPIO2 GPIO1 GPIO0 GPIO9 GPIO8 GPIO7 GPIO6 GPIO5 GPIO4 CHIP_EN Figure 6: ESP8684-WROOM-02UC Schematics Espressif Systems 29 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 9 Peripheral Schematics 9 Peripheral Schematics This is the typical application circuit of the module connected with peripheral components (for example, power supply, antenna, reset button, JTAG interface, and UART interface). 5 5 4 4 3 3 2 2 1 1 D D C C B B A A ESP8684-WROOM-02C ESP8684-WROOM-02UC GND GND VDD33 GNDGND GND VDD33 GND GNDGND VDD33 C4 0.1uF C1 10uF C3 TBD U1 3V3 1 IO8 7 IO7 6 IO6 5 IO5 4 IO4 3 EN 2 IO9 8 GND 9 IO0 18 IO1 17 IO2 16 IO3 15 EPAD 19 IO10 10 IO18 14 NC 13 TXD 12 RXD 11 C2 0.1uF J2 Boot Option 1 1 2 2 SW1 J1 UART 1 1 2 2 3 3 4 4 R1 TBD R2 0 IO0 IO1 IO2 IO3 IO18 IO10 EN 3V3 IO4 IO5 IO6 IO7 IO8 IO9 RX0 TX0 EN Figure 7: Peripheral Schematics • Soldering the EPAD to the ground of the base board is not a must, however, it can optimize thermal performance. If you choose to solder it, please apply the correct amount of soldering paste. Too much soldering paste may increase the gap between the module and the baseboard. As a result, the adhesion between other pins and the baseboard may be poor. • To ensure that the power supply to the ESP8684 chip is stable during power-up, it is advised to add an RC delay circuit at the EN pin. The recommended setting for the RC delay circuit is usually R = 10 kΩ and C = 1 µF. However, specific parameters should be adjusted based on the power-up timing of the module and the power-up and reset sequence timing of the chip. For ESP8684’s power-up and reset sequence timing diagram, please refer to Section Power Scheme in ESP8684 Series Datasheet. • UART0 is used to download firmware and log output. When using the AT firmware, please note that the UART GPIO is already configured (refer to Hardware Connection). It is recommended to use the default configuration. Espressif Systems 30 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 10 Physical Dimensions 10 Physical Dimensions 10.1 Module Dimensions 3.2±0.15 0.8 12.37 15.7 Ø0.5 0.71 1.15 20±0.15 6 18 x 0.9 12 0.9 1.5 Top View Side View Bottom View 18 x 0.85 18 x 0.9 18±0.15 18 x 0.45 Unit: mm 18 x Ø0.55 2.80 0.55 5.47 9.47 1.60 2.80 Figure 8: ESP8684-WROOM-02C Physical Dimensions Top View Side View Bottom View 18 x 0.85 18 x 0.9 Unit: mm 2.80 0.55 5.47 9.47 1.60 2.80 3.2±0.15 0.8 0.78 1.12 14.3±0.15 18 x 0.9 12 0.9 1.5 18±0.15 18 x 0.45 12.75 15.75 8.85 11.55 2.3 2.75 Ø0.5 18 x Ø0.55 Figure 9: ESP8684-WROOM-02UC Physical Dimensions Note: For information about tape, reel, and product marking, please refer to ESP8684 Module Packaging Information. Espressif Systems 31 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 10 Physical Dimensions 10.2 Dimensions of External Antenna Connector ESP8684-WROOM-02UC uses the first generation external antenna connector as shown in Figure 10 Dimensions of External Antenna Connector. This connector is compatible with the following connectors: • U.FL Series connector from Hirose • MHF I connector from I-PEX • AMC connector from Amphenol Unit: mm Figure 10: Dimensions of External Antenna Connector The external antenna used for ESP8684-WROOM-02UC during certification testing is the first generation Espressif Systems 32 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 10 Physical Dimensions monopole antenna, with material code TFPD05H08750011. The module does not include an external antenna upon shipment. If needed, select a suitable external antenna based on the product’s usage environment and performance requirements. It is recommended to select an antenna that meets the following requirements: • 2.4 GHz band • 50 Ω impedance • The maximum gain does not exceed 2.33 dBi, the gain of the antenna used for certification • The connector matches the specifications shown in Figure 10 Dimensions of External Antenna Connector Note: If you use an external antenna of a different type or gain, additional testing, such as EMC, may be required beyond the existing antenna test reports for Espressif modules. Specific requirements depend on the certification type. Espressif Systems 33 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 11 PCB Layout Recommendations 11 PCB Layout Recommendations 11.1 PCB Land Pattern This section provides the following resources for your reference: • Figures for recommended PCB land patterns with all the dimensions needed for PCB design. See Figure 11 ESP8684-WROOM-02C Recommended PCB Land Pattern and Figure 12 ESP8684-WROOM-02UC Recommended PCB Land Pattern. • Source files of recommended PCB land patterns to measure dimensions not covered in Figure 11 and Figure 12. You can view the source files for ESP8684-WROOM-02C and ESP8684-WROOM-02UC with Autodesk Viewer. • 3D models of ESP8684-WROOM-02C and ESP8684-WROOM-02UC. Please make sure that you download the 3D model file in .STEP format (beware that some browsers might add .txt). Unit: mm Copper 1 9 18 10 Antenna Area 6 20 1.5 18 x 1.5 0.5 18 0.5 17.5 7.1 18x0.90 0.90 2.80 2.80 0.55 1.60 5.47 9.47 Figure 11: ESP8684-WROOM-02C Recommended PCB Land Pattern Espressif Systems 34 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 11 PCB Layout Recommendations Unit: mm Copper 1 9 18 10 14.3 1.5 18 x 1.5 0.5 18 0.5 17.5 1.4 18x0.90 0.90 2.80 2.80 0.55 1.60 5.47 9.47 Figure 12: ESP8684-WROOM-02UC Recommended PCB Land Pattern 11.2 Module Placement for PCB Design If module-on-board design is adopted, attention should be paid while positioning the module on the base board. The interference of the base board on the module’s antenna performance should be minimized. For details about module placement for PCB design, please refer to ESP8684 Hardware Design Guidelines > Section Positioning a Module on a Base Board. Espressif Systems 35 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 12 Product Handling 12 Product Handling 12.1 Storage Conditions The products sealed in moisture barrier bags (MBB) should be stored in a non-condensing atmospheric environment of < 40 °C and 90%RH. The module is rated at the moisture sensitivity level (MSL) of 3. After unpacking, the module must be soldered within 168 hours with the factory conditions 25±5 °C and 60%RH. If the above conditions are not met, the module needs to be baked. 12.2 Electrostatic Discharge (ESD) • Human body model (HBM): ±2000 V • Charged-device model (CDM): ±500 V 12.3 Reflow Profile Solder the module in a single reflow. 50 100 0 150 200 250 200 100 50 150 250 Time (s) 217 25 Preheating 150 – 200 °C 60 – 120 s Ramp-up 25 – 150 °C 60 – 90 s 1 – 3 °C/s Soldering ＞ 217 °C 60 – 90 s Peak temperature: 235 – 250 °C Peak time: 30 – 70 s Soldering time: ＞ 30 s Solder: Sn-Ag-Cu (SAC305) lead-free solder Temperature (°C) 180 230 Cooling ＜ 180 °C –5 ~ –1 °C/s Figure 13: Reflow Profile Espressif Systems 36 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 12 Product Handling 12.4 Ultrasonic Vibration Avoid exposing Espressif modules to vibration from ultrasonic equipment, such as ultrasonic welders or ultrasonic cleaners. This vibration may induce resonance in the in-module crystal and lead to its malfunction or even failure. As a consequence, the module may stop working or its performance may deteriorate. Espressif Systems 37 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 Related Documentation and Resources Related Documentation and Resources Related Documentation • ESP8684 Series Datasheet – Specifications of the ESP8684 hardware. • ESP8684 Technical Reference Manual – Detailed information on how to use the ESP8684 memory and peripherals. • ESP8684 Hardware Design Guidelines – Guidelines on how to integrate the ESP8684 into your hardware product. • ESP8684 Series SoC Errata – Descriptions of known errors in ESP8684 series of SoCs. • Certificates https://espressif.com/en/support/documents/certificates • ESP8684 Product/Process Change Notifications (PCN) https://espressif.com/en/support/documents/pcns?keys=ESP8684 • Documentation Updates and Update Notification Subscription https://espressif.com/en/support/download/documents Developer Zone • ESP-IDF Programming Guide for ESP8684 – Extensive documentation for the ESP-IDF development framework. • ESP-IDF and other development frameworks on GitHub. https://github.com/espressif • ESP32 BBS Forum – Engineer-to-Engineer (E2E) Community for Espressif products where you can post questions, share knowledge, explore ideas, and help solve problems with fellow engineers. https://esp32.com/ • The ESP Journal – Best Practices, Articles, and Notes from Espressif folks. https://blog.espressif.com/ • See the tabs SDKs and Demos, Apps, Tools, AT Firmware. https://espressif.com/en/support/download/sdks-demos Products • ESP8684 Series SoCs – Browse through all ESP8684 SoCs. https://espressif.com/en/products/socs?id=ESP8684 • ESP8684 Series Modules – Browse through all ESP8684-based modules. https://espressif.com/en/products/modules?id=ESP8684 • ESP8684 Series DevKits – Browse through all ESP8684-based devkits. https://espressif.com/en/products/devkits?id=ESP8684 • ESP Product Selector – Find an Espressif hardware product suitable for your needs by comparing or applying filters. https://products.espressif.com/#/product-selector?language=en Contact Us • See the tabs Sales Questions, Technical Enquiries, Circuit Schematic & PCB Design Review, Get Samples (Online stores), Become Our Supplier, Comments & Suggestions. https://espressif.com/en/contact-us/sales-questions Espressif Systems 38 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 Revision History Revision History Date Version Release notes 2025-07-15 v1.4 • Updated Chapter 10.2 Dimensions of External Antenna Connector 2025-03-14 v1.3 Updated Table 15 Wi-Fi RF Transmitter (TX) Characteristics and Table 16 Wi-Fi RF Transmitter (TX) Characteristics 2025-01-20 v1.2 • Table 1 Series Comparison and table 2 Series Comparison: – Update Ordering Code from ESP8684-WROOM-02C-H2 to ESP8684-WROOM-02C-H2X – Update Ordering Code from ESP8684-WROOM-02C-H4 to ESP8684-WROOM-02C-H4X – Update Ordering Code from ESP8684-WROOM-02UC-H2 to ESP8684-WROOM-02UC-H2X – Update Ordering Code from ESP8684-WROOM-02UC-H4 to ESP8684-WROOM-02UC-H4X 2024-12-23 v1.1 • In Chapter 1 Module Overview, renamed 1.2 Description to 1.2 Series Com- parison • In Chapter 3.1 Pin Layout, Add annotations to the antenna keepout zone • Improved the structure, formatting, and wording in: – Chapter 4 Boot Configurations (use to be Section 3.3 Strapping Pins) – Chapter 6 Electrical Characteristics and 7 RF Characteristics (used to be Chapter 4 Electrical Characteristics) – Chapter 10.1 Module Dimensions and 11 PCB Layout Recommenda- tions (used to be Chapter 7 Physical Dimensions and PCB Land Pattern) • Added Chapter 5 Peripherals • Added Chapter 11.2 Module Placement for PCB Design 2024-08-16 v1.0 Updated the following module variants, upgrading the maximum operating am- bient temperature to 105°C: • Removed ESP8684-WROOM-02C-N2, ESP8684-WROOM-02C-N4, ESP8684-WROOM-02UC-N2 and ESP8684-WROOM-02UC-N4 • Added ESP8684-WROOM-02C-H2, ESP8684-WROOM-02C-H4, ESP8684-WROOM-02UC-H2 and ESP8684-WROOM-02UC-H4 2024-01-09 v0.7 Added an item about Bluetooth 5.3 certification in Section 1.1 Features. 2023-02-21 v0.6 • Added information of ESP8684-WROOM-02UC • Added a note to table 3 Pin Description 2022-08-29 v0.5 Preliminary release Espressif Systems 39 Submit Documentation Feedback ESP8684-WROOM-02C & WROOM-02UC Datasheet v1.4 Disclaimer and Copyright Notice Information in this document, including URL references, is subject to change without notice. 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