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 SDIO Sampling and Driving Clock Edge Control 4.3 ROM Messages Printing Control 4.4 JTAG Signal Source Control 5 Peripherals 5.1 Functional 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 I2S Controller 5.2.1.5 USB Serial/JTAG Controller 5.2.1.6 LED PWM Controller 5.2.1.7 SDIO Slave Controller 5.2.2 Analog Signal Processing 5.2.2.1 SAR ADC 5.2.2.2 Temperature Sensor 5.2.2.3 Analog Voltage Comparator 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 6.5 Memory Specifications 7 RF Characteristics 7.1 Wi-Fi Radio (2.4 GHz) 7.1.1 Wi-Fi RF Transmitter (TX) Characteristics 7.1.2 Wi-Fi RF Receiver (RX) Characteristics 7.2 Bluetooth 5 (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 ESP32-C61-WROOM-1 ESP32-C61-WROOM-1U Datasheet Version1.1 Module that supports 2.4 GHz Wi-Fi 6 (802.11ax), Bluetooth ® 5 (LE) Built around ESP32-C61 series of SoCs, 32-bit RISC-V single-core microprocessor Flash up to 16 MB, PSRAM up to 8 MB Up to 23 GPIOs, rich set of peripherals On-board PCB antenna or external antenna connector ESP32-C61-WROOM-1 ESP32-C61-WROOM-1U 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://espressif.com/documentation/esp32-c61-wroom-1_wroom-1u_datasheet_en.pdf 1.1 Features CPU and On-Chip Memory • ESP32-C61 series of SoCs embedded, 32-bit RISC-V single-core microprocessor, up to 160 MHz • ROM: 256 KB • SRAM: 320 KB • Up to 8 MB PSRAM Wi-Fi • 1T1R in 2.4 GHz band • Operating frequency: 2412 ∼ 2484 MHz • IEEE 802.11ax-compliant – 20 MHz-only non-AP mode – MCS0 ~ MCS9 – Uplink and downlink OFDMA to enhance connectivity and performance in congested environments for IoT applications – Downlink MU-MIMO (multi-user, multiple input, multiple output) to increase network capacity – Beamformee that improves signal quality – Spatial reuse to maximize parallel transmissions – Target wake time (TWT) that optimizes power saving mechanisms • Fully compatible with IEEE 802.11b/g/n protocol – 20 MHz and 40 MHz bandwidth – Data rate up to 150 Mbps – Wi-Fi Multimedia (WMM) – TX/RX A-MPDU, TX/RX A-MSDU – Immediate Block ACK – Fragmentation and defragmentation – Transmission opportunity (TXOP) – Automatic Beacon monitoring (hardware TSF) – Four virtual Wi-Fi interfaces – Simultaneous support for Infrastructure BSS in Station mode, SoftAP mode, Station + SoftAP mode, and promiscuous mode Note that when ESP32-C61 scans in Station mode, the SoftAP channel will change along with the Station channel – 802.11mc FTM Bluetooth ® • Bluetooth LE • Bluetooth mesh • High power mode (20 dBm) • Speed: 125 Kbps, 500 Kbps, 1 Mbps, 2 Mbps • Advertising extensions • Multiple advertisement sets • Channel selection algorithm #2 • LE power control • Internal co-existence mechanism between Wi-Fi and Bluetooth to share the same antenna Espressif Systems 2 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 1 Module Overview Peripherals • GPIO, SPI, UART, I2C, I2S, LED PWM, USB Serial/JTAG controller, GDMA, On-chip debug functionality via JTAG, event task matrix, ADC, temperature sensor, brown-out detector, analog voltage comparator, general-purpose timers, system timer, and watchdog timers Integrated Components on Module • 40 MHz crystal oscillator • Quad SPI flash Antenna Options • ESP32-C61-WROOM-1: On-board PCB antenna • ESP32-C61-WROOM-1U: External antenna via a connector Operating Conditions • Operating voltage/Power supply: 3.0 ∼ 3.6 V • Operating ambient temperature: – 85 °C version module: –40 ∼ 85 °C – 105 °C version module: –40 ∼ 105 °C 1.2 Series Comparison ESP32-C61-WROOM-1 and ESP32-C61-WROOM-1U are two powerful, general-purpose Wi-Fi, and Bluetooth LE modules. The rich set of peripherals and high performance make the module an ideal choice for smart homes, industrial automation, health care, consumer electronics, etc. ESP32-C61-WROOM-1 comes with a PCB antenna. ESP32-C61-WROOM-1U comes with a connector for an external antenna. The information in this datasheet is applicable to both modules. A wide selection of module variants are available. The variant nomenclature is shown in Figure 1, and the series comparisons are listed in Table 1 and Table 2. The nomenclature for the module variants is as follows: ESP32-C61 -XX-XX H/N x R Flash size (MB) Ambient temperature (℃) H-40 ~ 105 N-40 ~ 85 Module name x PSRAM size (MB) PSRAM (optional) Figure 1: ESP32-C61 Module Variant Nomenclature Espressif Systems 3 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 1 Module Overview The series comparison for the two modules is as follows: Table 1: ESP32-C61-WROOM-1 (ANT) Series Comparison 1 Ambient Temp. 4 Size 5 Part Number 2 Flash 3 PSRAM Embedded Chip (°C) (mm) ESP32-C61-WROOM-1-N8R2 8 MB (Quad SPI) 2 MB ESP32-C61HR2 –40 ~ 85 18.0 × 25.5 × 3.1 ESP32-C61-WROOM-1-N8R8 8 MB (Quad SPI) 8 MB ESP32-C61HR8 –40 ~ 85 18.0 × 25.5 × 3.1 1 This table shares the same notes presented in Table 2 below. Table 2: ESP32-C61-WROOM-1U (CONN) Series Comparison Ambient Temp. 4 Size 5 Part Number 2 Flash 3 PSRAM Embedded Chip (°C) (mm) ESP32-C61-WROOM-1U-N8R2 8 MB (Quad SPI) 2 MB ESP32-C61HR2 –40 ~ 85 18.0 × 19.2 × 3.2 ESP32-C61-WROOM-1U-N8R8 8 MB (Quad SPI) 8 MB ESP32-C61HR8 –40 ~ 85 ESP32-C61-WROOM-1U-H16R2 16 MB (Quad SPI) 2 MB ESP32-C61HR2 –40 ~ 105 2 Variants with special flash, PSRAM sizes, or ambient temperatures are not listed individually. The flash can be customized up to 16 MB and the PSRAM can be customized up to 8 MB. For customization requests, please contact us. For module variants not listed, refer to Figure 1 ESP32-C61 Module Variant Nomenclature for the specific specifications. 3 For specifications, refer to Section 6.5 Memory Specifications. 4 Ambient temperature specifies the recommended temperature range of the environment immediately outside the Espressif module. 5 For details, refer to Section 10.1 Module Dimensions. 6 ESP32-C61-WROOM-1U uses ANT1 by default. To order the ANT2 model, add T2 to the general Part Number, for example: ESP32-C61-WROOM-1U-N8R2T2. At the core of the modules is ESP32-C61 *, a 32-bit RISC-V single-core processor. Note: For more information on ESP32-C61, please refer to ESP32-C61 Series Datasheet. 1.3 Applications • Smart Home • Industrial Automation • Health Care • Consumer Electronics • Smart Agriculture • POS Machines • Service Robot • Audio Devices • Generic Low-power IoT Sensor Hubs • Generic Low-power IoT Data Loggers Espressif Systems 4 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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 11 4 Boot Configurations 14 4.1 Chip Boot Mode Control 15 4.2 SDIO Sampling and Driving Clock Edge Control 16 4.3 ROM Messages Printing Control 16 4.4 JTAG Signal Source Control 17 5 Peripherals 18 5.1 Functional Overview 18 5.2 Peripheral Description 18 5.2.1 Connectivity Interface 18 5.2.1.1 UART Controller 18 5.2.1.2 SPI Controller 19 5.2.1.3 I2C Controller 20 5.2.1.4 I2S Controller 20 5.2.1.5 USB Serial/JTAG Controller 21 5.2.1.6 LED PWM Controller 21 5.2.1.7 SDIO Slave Controller 22 5.2.2 Analog Signal Processing 23 5.2.2.1 SAR ADC 23 5.2.2.2 Temperature Sensor 23 5.2.2.3 Analog Voltage Comparator 24 6 Electrical Characteristics 25 6.1 Absolute Maximum Ratings 25 6.2 Recommended Operating Conditions 25 6.3 DC Characteristics (3.3 V, 25 °C) 25 6.4 Current Consumption Characteristics 26 6.4.1 Current Consumption in Active Mode 26 6.4.2 Current Consumption in Other Modes 26 6.5 Memory Specifications 27 7 RF Characteristics 29 Espressif Systems 5 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 Contents 7.1 Wi-Fi Radio (2.4 GHz) 29 7.1.1 Wi-Fi RF Transmitter (TX) Characteristics 29 7.1.2 Wi-Fi RF Receiver (RX) Characteristics 30 7.2 Bluetooth 5 (LE) Radio 32 7.2.1 Bluetooth LE RF Transmitter (TX) Characteristics 32 7.2.2 Bluetooth LE RF Receiver (RX) Characteristics 33 8 Module Schematics 36 9 Peripheral Schematics 38 10 Physical Dimensions 40 10.1 Module Dimensions 40 10.2 Dimensions of External Antenna Connector 41 11 PCB Layout Recommendations 42 11.1 PCB Land Pattern 42 11.2 Module Placement for PCB Design 43 12 Product Handling 44 12.1 Storage Conditions 44 12.2 Electrostatic Discharge (ESD) 44 12.3 Reflow Profile 44 12.4 Ultrasonic Vibration 45 Related Documentation and Resources 46 Revision History 47 Espressif Systems 6 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 List of Tables List of Tables 1 ESP32-C61-WROOM-1 (ANT) Series Comparison 1 4 2 ESP32-C61-WROOM-1U (CONN) Series Comparison 4 3 ESP32-C61-WROOM-1 Pin Definitions 1 11 4 ESP32-C61-WROOM-1U Pin Definitions 12 5 Default Configuration of Strapping Pins 14 6 Description of Timing Parameters for the Strapping Pins 15 7 Chip Boot Mode Control 15 8 SDIO Input Sampling Edge/Output Driving Edge Control 16 9 UART0 ROM Message Printing Control 16 10 USB Serial/JTAG ROM Message Printing Control 17 11 JTAG Signal Source Control 17 12 Absolute Maximum Ratings 25 13 Recommended Operating Conditions 25 14 DC Characteristics (3.3 V, 25 °C) 25 15 Current Consumption for Wi-Fi (2.4 GHz) in Active Mode 26 16 Current Consumption for Bluetooth LE in Active Mode 26 17 Current Consumption in Modem-sleep Mode 26 17 Current Consumption in Modem-sleep Mode 27 18 Current Consumption in Low-Power Modes 27 19 Flash Specifications 27 20 PSRAM Specifications 28 21 Wi-Fi RF Characteristics 29 22 TX Power with Spectral Mask and EVM Meeting 802.11 Standards 29 23 TX EVM Test 1 29 24 RX Sensitivity 30 25 Maximum RX Level 31 26 RX Adjacent Channel Rejection 31 27 Bluetooth LE RF Characteristics 32 28 Bluetooth LE - Transmitter Characteristics - 1 Mbps 32 29 Bluetooth LE - Transmitter Characteristics - 2 Mbps 32 30 Bluetooth LE - Transmitter Characteristics - 125 Kbps 33 31 Bluetooth LE - Transmitter Characteristics - 500 Kbps 33 32 Bluetooth LE - Receiver Characteristics - 1 Mbps 33 33 Bluetooth LE - Receiver Characteristics - 2 Mbps 34 34 Bluetooth LE - Receiver Characteristics - 125 Kbps 35 35 Bluetooth LE - Receiver Characteristics - 500 Kbps 35 Espressif Systems 7 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 List of Figures List of Figures 1 ESP32-C61 Module Variant Nomenclature 3 2 ESP32-C61-WROOM-1 Block Diagram 9 3 ESP32-C61-WROOM-1U Block Diagram 9 4 ESP32-C61-WROOM-1 Pin Layout (Top View) 10 5 ESP32-C61-WROOM-1U Pin Layout (Top View) 11 6 Visualization of Timing Parameters for the Strapping Pins 15 7 ESP32-C61-WROOM-1 Schematics 36 8 ESP32-C61-WROOM-1U Schematics 37 9 ESP32-C61-WROOM-1 Peripheral Schematics 38 10 ESP32-C61-WROOM-1U Peripheral Schematics 38 11 ESP32-C61-WROOM-1 Physical Dimensions 40 12 ESP32-C61-WROOM-1U Physical Dimensions 40 13 Dimensions of External Antenna Connector 41 14 ESP32-C61-WROOM-1 Recommended PCB Land Pattern 42 15 ESP32-C61-WROOM-1U Recommended PCB Land Pattern 43 16 Reflow Profile 44 Espressif Systems 8 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 2 Block Diagram 2 Block Diagram RF Matching 40 MHz Crystal ESP32-C61-WROOM-1 GPIOs Antenna QSPI Flash SPICS0 SPIQ SPIWP SPIHD SPICLK SPID VDD_SPI ESP32-C61 PSRAM(opt.) (QSPI) GND 3V3 EN ESP32-C61 RF Matching 40 MHz Crystal ESP32-C61-WROOM-1U GPIOs QSPI Flash SPICS0 SPIQ SPIWP SPIHD SPICLK SPID VDD_SPI PSRAM(opt.) (QSPI) GND 3V3 EN Antenna1 Antenna2 Figure 2: ESP32-C61-WROOM-1 Block Diagram RF Matching 40 MHz Crystal ESP32-C61-WROOM-1 GPIOs Antenna QSPI Flash SPICS0 SPIQ SPIWP SPIHD SPICLK SPID VDD_SPI ESP32-C61 PSRAM(opt.) (QSPI) GND 3V3 EN ESP32-C61 RF Matching 40 MHz Crystal ESP32-C61-WROOM-1U GPIOs QSPI Flash SPICS0 SPIQ SPIWP SPIHD SPICLK SPID VDD_SPI PSRAM(opt.) (QSPI) GND 3V3 EN Antenna1 Antenna2 Figure 3: ESP32-C61-WROOM-1U Block Diagram Espressif Systems 9 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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. Pin Layout (Top View) 3V3 EN IO4 IO5 IO6 IO7 IO13 28 27 26 25 24 23 22 21 20 19 18 17 16 15 GND IO2 IO3 TX0 RX0 IO24 NC IO23 IO22 IO28 IO27 IO26 IO25 IO9 29 GND Keepout Zone GND GND GND GND GND GNDGNDGND 2 3 4 5 6 7 8 9 10 11 12 13 14 IO0 IO1 IO8 IO29 IO12 NC/IO14 1 GND 3V3 EN IO4 IO5 IO6 IO7 IO13 28 27 26 25 24 23 22 21 20 19 18 17 16 15 GND IO2 IO3 TX0 RX0 IO24 NC IO23 IO22 IO28 IO27 IO26 IO25 IO9 29 GND GND GND GND GND GND GNDGNDGND 2 3 4 5 6 7 8 9 10 11 12 13 14 IO0 IO1 IO8 IO29 IO12 NC/IO14 1 GND ESP32-C61-WROOM-1 ESP32-C61-WROOM-1U 32 31 30 GND ANT2 GND ANT1 Figure 4: ESP32-C61-WROOM-1 Pin Layout (Top View) Espressif Systems 10 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 3 Pin Definitions Pin Layout (Top View) 3V3 EN IO4 IO5 IO6 IO7 IO13 28 27 26 25 24 23 22 21 20 19 18 17 16 15 GND IO2 IO3 TX0 RX0 IO24 NC IO23 IO22 IO28 IO27 IO26 IO25 IO9 29 GND Keepout Zone GND GND GND GND GND GNDGNDGND 2 3 4 5 6 7 8 9 10 11 12 13 14 IO0 IO1 IO8 IO29 IO12 NC/IO14 1 GND 3V3 EN IO4 IO5 IO6 IO7 IO13 28 27 26 25 24 23 22 21 20 19 18 17 16 15 GND IO2 IO3 TX0 RX0 IO24 NC IO23 IO22 IO28 IO27 IO26 IO25 IO9 29 GND GND GND GND GND GND GNDGNDGND 2 3 4 5 6 7 8 9 10 11 12 13 14 IO0 IO1 IO8 IO29 IO12 NC/IO14 1 GND ESP32-C61-WROOM-1 ESP32-C61-WROOM-1U 32 31 30 GND ANT2 GND ANT1 Figure 5: ESP32-C61-WROOM-1U Pin Layout (Top View) 3.2 Pin Description ESP32-C61-WROOM-1 module has 29 pins and ESP32-C61-WROOM-1U module has 32 pins. See pin definitions in Table 3 Pin Description and Table 4 Pin Description. For peripheral pin configurations, please refer to ESP32-C61 Series Datasheet. Table 3: ESP32-C61-WROOM-1 Pin Definitions 1 Name No. Type 2 Function GND 1 P Ground 3V3 2 P Power supply EN 3 I High: on, enables the chip. Low: off, the chip powers off. Note: Do not leave the EN pin floating. IO4 4 I/O/T MTDI, GPIO4, LP_GPIO4, ADC1_CH2, FSPIWP IO5 5 I/O/T MTCK, GPIO5, LP_GPIO5, ADC1_CH3 IO6 6 I/O/T MTDO, GPIO6, LP_GPIO6, FSPICLK IO7 7 I/O/T GPIO7, FSPID IO0 8 I/O/T XTAL_32K_P, GPIO0, LP_GPIO0 Cont’d on next page Espressif Systems 11 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 3 Pin Definitions Table 3 – cont’d from previous page Name No. Type 2 Function IO1 9 I/O/T XTAL_32K_N, GPIO1, LP_GPIO1, ADC1_CH0 IO8 10 I/O/T GPIO8, ZCD0, FSPICS0 IO29 11 I/O/T GPIO29 NC/IO14 12 I/O/T NC/GPIO14 3 IO12 13 I/O/T USB_D-, GPIO12 IO13 14 I/O/T USB_D+, GPIO13 IO9 15 I/O/T GPIO9, ZCD1 IO25 16 I/O/T GPIO25, SDIO_CMD IO26 17 I/O/T GPIO26, SDIO_CLK IO27 18 I/O/T GPIO27, SDIO_DATA0 IO28 19 I/O/T GPIO28, SDIO_DATA1 IO22 20 I/O/T GPIO22, SDIO_DATA2 IO23 21 I/O/T GPIO23, SDIO_DATA3 NC 22 — NC IO24 23 I/O/T GPIO24 RX0 24 I/O/T U0RXD, GPIO10 TX0 25 I/O/T U0TXD, GPIO11 IO3 26 I/O/T MTMS, GPIO3, LP_GPIO3, ADC1_CH1, FSPIHD IO2 27 I/O/T GPIO2, LP_GPIO2, FSPIQ GND 28 P Ground EPAD 29 P Ground 1 This table shares the notes 2 and 3 presented in Table 4 below. Table 4: ESP32-C61-WROOM-1U Pin Definitions Name No. Type 2 Function GND 1 P Ground 3V3 2 P Power supply EN 3 I High: on, enables the chip. Low: off, the chip powers off. Note: Do not leave the EN pin floating. IO4 4 I/O/T MTDI, GPIO4, LP_GPIO4, ADC1_CH2, FSPIWP IO5 5 I/O/T MTCK, GPIO5, LP_GPIO5, ADC1_CH3 IO6 6 I/O/T MTDO, GPIO6, LP_GPIO6, FSPICLK IO7 7 I/O/T GPIO7, FSPID IO0 8 I/O/T XTAL_32K_P, GPIO0, LP_GPIO0 IO1 9 I/O/T XTAL_32K_N, GPIO1, LP_GPIO1, ADC1_CH0 IO8 10 I/O/T GPIO8, ZCD0, FSPICS0 IO29 11 I/O/T GPIO29 NC/IO14 12 I/O/T NC/GPIO14 3 IO12 13 I/O/T USB_D-, GPIO12 Cont’d on next page Espressif Systems 12 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 3 Pin Definitions Table 4 – cont’d from previous page Name No. Type 2 Function IO13 14 I/O/T USB_D+, GPIO13 IO9 15 I/O/T GPIO9, ZCD1 IO25 16 I/O/T GPIO25, SDIO_CMD IO26 17 I/O/T GPIO26, SDIO_CLK IO27 18 I/O/T GPIO27, SDIO_DATA0 IO28 19 I/O/T GPIO28, SDIO_DATA1 IO22 20 I/O/T GPIO22, SDIO_DATA2 IO23 21 I/O/T GPIO23, SDIO_DATA3 NC 22 — NC IO24 23 I/O/T GPIO24 RX0 24 I/O/T U0RXD, GPIO10 TX0 25 I/O/T U0TXD, GPIO11 IO3 26 I/O/T MTMS, GPIO3, LP_GPIO3, ADC1_CH1, FSPIHD IO2 27 I/O/T GPIO2, LP_GPIO2, FSPIQ GND 28 P Ground EPAD 29 P Ground GND 30 P Ground ANT2 4 31 I/O RF input and output GND 32 P Ground 2 P: power supply; I: input; O: output; T: high impedance. 3 In modules with embedded SPI PSRAM, this pin is already used as SPICS1 for SPI PSRAM and cannot be used for other functions. In modules without embedded SPI PSRAM, this pin can be used as GPIO14. 4 By default, ESP32-C61-WROOM-1U uses ANT1, and ANT2 is disabled. To use ANT2, please contact us. Espressif Systems 13 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 4 Boot Configurations 4 Boot Configurations Note: The content below is excerpted from ESP32-C61 Series Datasheet > Section Boot Configurations. For the strapping pin mapping between the chip and modules, please refer to Chapter 8 Module Schematics. The chip allows for configuring the following boot parameters through strapping-pins and eFuse parameter at power-up or a hardware reset, without microcontroller interaction. • Chip boot mode – Strapping pin: GPIO8 and GPIO9 • SDIO sampling and driving clock edge – Strapping pin: MTDI and MTMS • ROM message printing – Strapping pin: GPIO8 – eFuse parameter: EFUSE_UART_PRINT_CONTROL and EFUSE_DIS_USB_SERIAL_JTAG_ROM_PRINT • JTAG signal source – Strapping pin: GPIO7 – eFuse parameter: EFUSE_DIS_PAD_JTAG, EFUSE_DIS_USB_JTAG, and EFUSE_JTAG_SEL_ENABLE 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. 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 5: Default Configuration of Strapping Pins Strapping Pin Default Configuration Bit Value MTMS Floating – MTDI Floating – GPIO7 Floating – GPIO8 Floating – GPIO9 Pull-up 1 To change the bit values, the strapping pins should be connected to external pull-down/pull-up resistances. If the ESP32-C61 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 Espressif Systems 14 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 4 Boot Configurations 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 6 and Figure 6. Table 6: Description of Timing Parameters for the Strapping Pins Parameter Description Min (ms) t SU Setup time is the time reserved for the power rails to stabilize before the CHIP_PU pin is pulled high to activate the chip. 0 t H Hold time is the time reserved for the chip to read the strapping pin values after CHIP_PU is already high and before these pins start operating as regular IO pins. 3 Strapping pin V IH_nRST V IH t SU t H CHIP_PU Figure 6: 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 7 Chip Boot Mode Control. Table 7: Chip Boot Mode Control Boot Mode GPIO8 GPIO9 SPI Boot 1 Any value 1 Joint Download Boot 2 1 0 1 Bold marks the default value and configura- tion. 2 Joint Download Boot mode supports the fol- lowing download methods: • USB-Serial-JTAG Download Boot • UART Download Boot • SDIO Slave 2.0 Download Boot Espressif Systems 15 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 4 Boot Configurations In SPI Boot mode, the ROM bootloader loads and executes the program from SPI flash to boot the system. In Joint Download Boot mode, users can download binary files into flash using UART0, USB or SDIO Slave interfaces and execute it in SPI Boot mode. In Joint Download Boot mode, it is also possible to download binary files into SRAM using UART0, USB or SDIO Slave interfaces and execute it from SRAM. 4.2 SDIO Sampling and Driving Clock Edge Control The strapping pin MTMS and MTDI can be used to decide on which clock edge to sample signals and drive output lines. See Table 8 SDIO Input Sampling Edge/Output Driving Edge Control. Table 8: SDIO Input Sampling Edge/Output Driving Edge Control Edge behavior MTMS MTDI Falling edge sampling, falling edge output 0 0 Falling edge sampling, rising edge output 0 1 Rising edge sampling, falling edge output 1 0 Rising edge sampling, rising edge output 1 1 1 MTMS and MTDI are floating by default, so above are not default configurations. 4.3 ROM Messages Printing Control During the boot process, the messages by the ROM code can be printed to: • (Default) UART0 and USB Serial/JTAG controller • USB Serial/JTAG controller • UART0 LP_AON_STORE4_REG[0], EFUSE_UART_PRINT_CONTROL and GPIO8 control ROM messages printing to UART0 as shown in Table 9 UART0 ROM Message Printing Control. Table 9: UART0 ROM Message Printing Control UART0 ROM Code Printing EFUSE_UART_PRINT_CONTROL GPIO8 Register 1 Always enabled 2 0 Ignored 0 Enabled 1 0 Disabled 1 Disabled 2 0 Enabled 1 Always disabled 3 Ignored Disabled Ignored Ignored 1 1 Register: LP_AON_STORE4_REG[0] 2 Bold marks the default value and configuration. Espressif Systems 16 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 4 Boot Configurations EFUSE_DIS_USB_SERIAL_JTAG_ROM_PRINT and LP_AON_STORE4_REG[0] control the printing to USB Serial/JTAG controller as shown in Table 10 USB Serial/JTAG ROM Message Printing Control. Table 10: USB Serial/JTAG ROM Message Printing Control USB Serial/JTAG ROM Mes- sage Printing Control LP_AON_STORE4_REG[0] EFUSE_DIS_USB_SERIAL_JTAG _ROM_PRINT Enabled 0 0 Disabled 0 1 1 Ignored 1 Bold marks the default value and configuration. 4.4 JTAG Signal Source Control The strapping pin GPIO7 can be used to control the source of JTAG signals during the early boot process. This pin does not have any internal pull resistors and the strapping value must be controlled by the external circuit that cannot be in a high impedance state. As Table 11 shows, GPIO7 is used in combination with EFUSE_DIS_PAD_JTAG, EFUSE_DIS_USB_JTAG, and EFUSE_JTAG_SEL_ENABLE. Table 11: JTAG Signal Source Control eFuse 1 1 eFuse 2 2 eFuse 3 3 GPIO7 JTAG Signal Source 0 0 0 x 4 USB Serial/JTAG Controller 5 1 1 0 JTAG pins MTDI, MTCK, MTMS and MTDO0 x x x 0 1 x x 1 0 x x USB Serial/JTAG Controller 1 1 x x JTAG is disabled 1 x x x 1 eFuse 1: EFUSE_DIS_PAD_JTAG 2 eFuse 2: EFUSE_DIS_USB_JTAG 3 eFuse 3: EFUSE_JTAG_SEL_ENABLE 4 x: x indicates that the value has no effect on the result and can be ignored. 5 Bold marks the default value and configuration. Espressif Systems 17 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals 5 Peripherals 5.1 Functional Overview ESP32-C61 integrates a rich set of peripherals including GPIO, SPI, UART, I2C, I2S, LED PWM, USB Serial/JTAG controller, GDMA, On-chip debug functionality via JTAG, event task matrix, ADC, temperature sensor, brown-out detector, analog voltage comparator, general-purpose timers, system timer, and watchdog timers etc. To learn more about on-chip components, please refer to ESP32-C61 Series Datasheet > Section Functional Description. Note: The content below is sourced from ESP32-C61 Series Datasheet > Section Peripherals. Some information may not be applicable to ESP32-C61-WROOM-1 and ESP32-C61-WROOM-1U as not all the IO signals are exposed on the module. To learn more about peripheral signals, please refer to ESP32-C61 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 ESP32-C61 chip facilitates the transmission and reception of asynchronous serial data between the chip and external UART devices. It supports three UART interfaces. Feature List • Programmable baud rates up to 5 MBaud • RAM shared by TX FIFOs and RX FIFOs • Support for various lengths of data bits and stop bits • Parity bit support • Special character AT_CMD detection • RS485 protocol support • IrDA protocol support • High-speed data communication using GDMA • Receive timeout feature • UART as the wake-up source Espressif Systems 18 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals • Software and hardware flow control Pin Assignment The pins connected to transmit and receive signals (U0TXD and U0RXD) for UART0 are multiplexed with GPIO10 ~ GPIO11 via IO MUX. Other signals can be routed to any GPIOs via the GPIO matrix. 5.2.1.2 SPI Controller ESP32-C61 has the following SPI interfaces: • SPI0 used by ESP32-C61’s cache and GDMA to access in-package or off-package flash/PSRAM • SPI1 used by the CPU to access in-package or off-package flash/PSRAM • SPI2 is a general-purpose SPI controller with access to general-purpose DMA channels SPI0 and SPI1 are reserved for system use, and only SPI2 is available for users. Features of SPI0 and SPI1 • Supports Single SPI, Dual SPI, Quad SPI, QPI modes • Data transmission is in bytes Features of SPI2 • Supports operation as a master or slave • Support for DMA • Supports Single SPI, Dual SPI, Quad SPI, QPI modes • Configurable clock polarity (CPOL) and phase (CPHA) • Configurable clock frequency • Data transmission is in bytes • Configurable read and write data bit order: most-significant bit (MSB) first, or least-significant bit (LSB) first • As a master – Supports 2-line full-duplex communication with clock frequency up to 80 MHz – Supports 1-, 2-, 4-line half-duplex communication with clock frequency up to 80 MHz – Provides six FSPICS… pins for connection with six independent SPI slaves – Configurable CS setup time and hold time • As a slave – Supports 2-line full-duplex communication with clock frequency up to 60 MHz – Supports 1-, 2-, 4-line half-duplex communication with clock frequency up to 60 MHz Espressif Systems 19 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals Pin Assignment For SPI0/1, the pins are multiplexed with GPIO14 ~ GPIO17 and GPIO19 ~ GPIO20 via the IO MUX. For SPI2, the pins for data and clock signals are multiplexed with GPIO2, GPIO7, and JTAG interface via the IO MUX. The pins for chip select signals for multiplexed with GPIO8 via the IO MUX. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. 5.2.1.3 I2C Controller The I2C Controller supports communication between the master and slave devices using the I2C bus. Feature List • Communication with multiple external devices • Master and slave modes for I2C • Standard mode (100 Kbit/s) and fast mode (400 Kbit/s) • SCL clock stretching in slave mode • Programmable digital noise filtering • Support for 7-bit and 10-bit addressing, as well as dual address mode Pin Assignment For regular I2C, the pins used can be chosen from any GPIOs via the GPIO Matrix. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. 5.2.1.4 I2S Controller The I2S Controller in the ESP32-C61 chip provides a flexible communication interface for streaming digital data in multimedia applications, particularly digital audio applications. Feature List • Master mode and slave mode • Full-duplex and half-duplex communications • Separate TX and RX units that can work independently or simultaneously • A variety of audio standards supported: – TDM Philips standard – TDM MSB alignment standard – TDM PCM standard – PDM standard • PCM-to-PDM TX interface • Configurable high-precision BCK clock, with frequency up to 40 MHz Espressif Systems 20 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals – Sampling frequencies can be 8 kHz, 16 kHz, 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 128 kHz, 192 kHz, etc. • 8-/16-/24-/32-bit data communication • Direct Memory Access (DMA) • A-law and µ-law compression/decompression algorithms for improved signal-to-quantization noise ratio • Flexible data format control Pin Assignment The pins for the I2S Controller can be chosen from any GPIOs via the GPIO Matrix. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. 5.2.1.5 USB Serial/JTAG Controller The USB Serial/JTAG controller in the ESP32-C61 chip provides an integrated solution for communicating to the chip over a standard USB CDC-ACM serial port as well as a convenient method for JTAG debugging. It eliminates the need for external chips or JTAG adapters, saving space and reducing cost. Feature List • USB 2.0 full speed compliant, capable of up to 12 Mbit/s transfer speed (Note that this controller does not support the faster 480 Mbit/s high-speed transfer mode) • CDC-ACM virtual serial port and JTAG adapter functionality • CDC-ACM: – CDC-ACM adherent serial port emulation (plug-and-play on most modern OSes) – Host controllable chip reset and entry into download mode • JTAG adapter functionality: – Fast communication with CPU debugging core using a compact representation of JTAG instructions • Support for reprogramming of attached flash memory through the ROM startup code • Internal PHY Pin Assignment The pins for the USB Serial/JTAG Controller are multiplexed with GPIO12 ~ GPIO13 via IO MUX. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. 5.2.1.6 LED PWM Controller The LED PWM controller can generate independent digital waveform on six channels. The LED PWM controller supports: Espressif Systems 21 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals Feature List • Generating digital waveform with configurable periods and duty cycle. The resolution of duty cycle can be up to 20 bits • Multiple clock sources, including 80 MHz PLL clock, external main crystal clock, and internal fast RC oscillator • Operation when the CPU is in Light-sleep mode • Gradual increase or decrease of duty cycle, which is useful for the LED RGB color-gradient generator • Up to 16 duty cycle ranges for gamma curve generation, each can be independently configured in terms of duty cycle direction (increase or decrease), step size, the number of steps, and step frequency 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 ESP32-C61 Series Datasheet > Section IO Pins. 5.2.1.7 SDIO Slave Controller The SDIO Slave controller in ESP32-C61 provides hardware support for the Secure Digital Input/Output (SDIO) device interface. It allows an SDIO host to access ESP32-C61 via an SDIO bus protocol. Feature List • compatible with SDIO Physical Layer Specification V2.00 and SDIO Specifications V2.00 • support SPI, 1-bit SDIO, and 4-bit SDIO transfer modes • clock range of 0 ~ 50 MHz • configurable sample and drive clock edge • integrated and SDIO-accessible registers for information interaction • support SDIO interrupts • automatic padding data and discarding the padded data on the SDIO bus • block size up to 512 bytes • interrupt vector between the host and slave for bidirectional interrupt • support DMA for data transfer • support wake-up from sleep when connection is retained Pin Assignment The pins for the SDIO Slave controller are multiplexed with GPIO22 ~ GPIO23, and GPIO25 ~ GPIO28 via IO MUX. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. Espressif Systems 22 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals 5.2.2 Analog Signal Processing This subsection describes components on the chip that sense and process real-world data. 5.2.2.1 SAR ADC ESP32-C61 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 four pins • Attenuation of input signals for voltage conversion • Software-triggered one-time sampling • Timer-triggered multi-channel scanning • DMA continuous conversion for seamless data transfer • Two filters with configurable filter coefficient • Threshold monitoring which helps to trigger an interrupt • Support for Event Task Matrix Pin Assignment The SAR ADC pins are multiplexed with GPIO1 and GPIO3 ~ GPIO5. These GPIOs are also multiplexed with LP_GPIO1, LP_GPIO3 ~ LP_GPIO5, and with the JTAG interface. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. 5.2.2.2 Temperature Sensor The Temperature Sensor in the ESP32-C61 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 • Hardware automatic triggering and temperature monitoring • Configurable temperature offset based on the environment to improve the accuracy • Adjustable measurement range • Two automatic monitoring wake-up modes: absolute value mode and incremental value mode • Support for Event Task Matrix Espressif Systems 23 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 5 Peripherals 5.2.2.3 Analog Voltage Comparator ESP32-C61 provides a group of analog voltage comparators which contain two special pads. This peripheral can be used to compare the voltages of the two pads or compare the voltage of one pad with an internally adjustable stable voltage. Feature List • Internal or external reference voltage • Supported internal reference voltage ranging from 0 to 0.7 × VDD_PST • Support for ETM • Interrupt triggered when the measured voltage reaches the reference voltage Pin Assignment The analog voltage comparator has dedicated pads, GPIO8 and GPIO9. GPIO9 is the test pad, and GPIO8 serves as the reference pad when using an external reference voltage. For more information about the pin assignment, see ESP32-C61 Series Datasheet > Section IO Pins. Espressif Systems 24 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 6 Electrical Characteristics 6 Electrical Characteristics 6.1 Absolute Maximum Ratings Stresses above those listed in Table 12 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 13 Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Table 12: Absolute Maximum Ratings Symbol Parameter Min Max Unit VDD33 Power supply voltage –0.3 3.6 V 6.2 Recommended Operating Conditions Table 13: 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 85 °C version –40 — 85 °C 105 °C version 105 6.3 DC Characteristics (3.3 V, 25 °C) Table 14: 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 25 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 6 Electrical Characteristics 1 VDD is the I/O voltage for pins of a particular power domain. 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 15: Current Consumption for Wi-Fi (2.4 GHz) in Active Mode Work Mode RF Condition Description Peak (mA) Active (RF working) TX 802.11b, 1 Mbps, DSSS @20.5 dBm 370 802.11g, 54 Mbps, OFDM @18.5 dBm 307 802.11n, HT20, MCS7 @17.5 dBm 285 802.11n, HT40, MCS7 @17 dBm 267 802.11ax, MCS9 @14.5 dBm 238 RX 802.11b/g/n, HT20 88 802.11n, HT40 90 802.11ax, HE20 88 Table 16: Current Consumption for Bluetooth LE in Active Mode Work Mode RF Condition Description Peak (mA) Active (RF working) TX Bluetooth LE @ 18 dBm 300 Bluetooth LE @ 9 dBm 166 Bluetooth LE @ 0 dBm 135 Bluetooth LE @ –15 dBm 96 RX Bluetooth LE 81 Note: The content below is excerpted from Section Power Consumption in Other Modes in ESP32-C61 Series Datasheet. 6.4.2 Current Consumption in Other Modes Table 17: Current Consumption in Modem-sleep Mode Typ (mA) Mode CPU Frequency (MHz) Description All Peripherals Clocks Disabled All Peripherals Clocks Enabled 1 Modem-sleep 2,3 160 WAITI 11 18 Espressif Systems 26 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 6 Electrical Characteristics Table 17: Current Consumption in Modem-sleep Mode Typ (mA) Mode CPU Frequency (MHz) Description All Peripherals Clocks Disabled All Peripherals Clocks Enabled 1 CPU while loop 16 23 Run CoreMark 21 28 80 WAITI 10 16 CPU while loop 12 19 Run CoreMark 15 21 40 WAITI 6 11 CPU while loop 7 12 Run CoreMark 9 13 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. Table 18: Current Consumption in Low-Power Modes Mode Description Typ (mA) Light-sleep CPU and wireless communication modules are powered down, pe- ripheral clocks are disabled, and all GPIOs are high-impedance 0.2 CPU, wireless communication modules and peripherals are pow- ered down, and all GPIOs are high-impedance 0.05 Deep-sleep LP timer and LP memory are powered on 0.01 Power off CHIP_PU is set to low level, the chip is powered off 0.001 6.5 Memory Specifications The data below is sourced from the memory vendor datasheet. These values are guaranteed through design and/or characterization but are not fully tested in production. Devices are shipped with the memory erased. Table 19: Flash Specifications Parameter Description Min Typ Max Unit VCC Power supply voltage (1.8 V) 1.65 1.80 2.00 V Power supply voltage (3.3 V) 2.7 3.3 3.6 V F C Maximum clock frequency 80 — — MHz — Program/erase cycles 100,000 — — cycles T RET Data retention time 20 — — years T P P Page program time — 0.8 5 ms T SE Sector erase time (4 KB) — 70 500 ms T BE1 Block erase time (32 KB) — 0.2 2 s Cont’d on next page Espressif Systems 27 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 6 Electrical Characteristics Table 19 – cont’d from previous page Parameter Description Min Typ Max Unit T BE2 Block erase time (64 KB) — 0.3 3 s T CE Chip erase time (16 Mb) — 7 20 s Chip erase time (32 Mb) — 20 60 s Chip erase time (64 Mb) — 25 100 s Chip erase time (128 Mb) — 60 200 s Chip erase time (256 Mb) — 70 300 s Table 20: PSRAM Specifications Parameter Description Min Typ Max Unit VCC Power supply voltage (1.8 V) 1.62 1.80 1.98 V Power supply voltage (3.3 V) 2.7 3.3 3.6 V F C Maximum clock frequency 80 — — MHz Espressif Systems 28 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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 (2.4 GHz) Table 21: Wi-Fi RF Characteristics Name Description Center frequency range of operating channel 2412 ~ 2484 MHz Wi-Fi wireless standard IEEE 802.11b/g/n/ax 7.1.1 Wi-Fi RF Transmitter (TX) Characteristics Table 22: TX Power with Spectral Mask and EVM Meeting 802.11 Standards Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 1 Mbps, DSSS — 20.5 — 802.11b, 11 Mbps, CCK — 20.5 — 802.11g, 6 Mbps, OFDM — 19.5 — 802.11g, 54 Mbps, OFDM — 18.5 — 802.11n, HT20, MCS0 — 18.5 — 802.11n, HT20, MCS7 — 17.5 — 802.11n, HT40, MCS0 — 18.0 — 802.11n, HT40, MCS7 — 17.0 — 802.11ax, HE20, MCS0 — 18.5 — 802.11ax, HE20, MCS9 — 14.5 — Table 23: TX EVM Test 1 Min Typ Limit Rate (dB) (dB) (dB) 802.11b, 1 Mbps, DSSS — –24.8 –10.0 802.11b, 11 Mbps, CCK — –24.8 –10.0 802.11g, 6 Mbps, OFDM — –24.5 –5.0 Cont’d on next page Espressif Systems 29 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 7 RF Characteristics Table 23 – cont’d from previous page Min Typ Limit Rate (dB) (dB) (dB) 802.11g, 54 Mbps, OFDM — –29.0 –25.0 802.11n, HT20, MCS0 — –23.0 –5.0 802.11n, HT20, MCS7 — –31.4 –27.0 802.11n, HT40, MCS0 — –25.8 –5.0 802.11n, HT40, MCS7 — –30.5 –27.0 802.11ax, HE20, MCS0 — –23.0 –5.0 802.11ax, HE20, MCS9 — –34.0 –32.0 1 EVM is measured at the corresponding typical TX power provided in Table 22 Wi-Fi RF Transmitter (TX) Characteristics above. 7.1.2 Wi-Fi RF Receiver (RX) Characteristics For RX tests, the PER (packet error rate) limit is 8% for 802.11b, and 10% for 802.11g/n/ax. Table 24: RX Sensitivity Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 1 Mbps, DSSS — –99.5 — 802.11b, 2 Mbps, DSSS — –96.0 — 802.11b, 5.5 Mbps, CCK — –93.5 — 802.11b, 11 Mbps, CCK — –90.0 — 802.11g, 6 Mbps, OFDM — –94.0 — 802.11g, 9 Mbps, OFDM — –93.0 — 802.11g, 12 Mbps, OFDM — –92.0 — 802.11g, 18 Mbps, OFDM — –89.5 — 802.11g, 24 Mbps, OFDM — –86.5 — 802.11g, 36 Mbps, OFDM — –83.0 — 802.11g, 48 Mbps, OFDM — –78.5 — 802.11g, 54 Mbps, OFDM — –77.5 — 802.11n, HT20, MCS0 — –94.0 — 802.11n, HT20, MCS1 — –92.0 — 802.11n, HT20, MCS2 — –89.5 — 802.11n, HT20, MCS3 — –86.0 — 802.11n, HT20, MCS4 — –83.0 — 802.11n, HT20, MCS5 — –78.5 — 802.11n, HT20, MCS6 — –77.0 — 802.11n, HT20, MCS7 — –75.0 — 802.11n, HT40, MCS0 — –91.0 — 802.11n, HT40, MCS1 — –89.5 — 802.11n, HT40, MCS2 — –87.0 — Cont’d on next page Espressif Systems 30 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 7 RF Characteristics Table 24 – cont’d from previous page Min Typ Max Rate (dBm) (dBm) (dBm) 802.11n, HT40, MCS3 — –83.5 — 802.11n, HT40, MCS4 — –80.5 — 802.11n, HT40, MCS5 — –76.0 — 802.11n, HT40, MCS6 — –74.0 — 802.11n, HT40, MCS7 — –73.0 — 802.11ax, HE20, MCS0 — –93.5 — 802.11ax, HE20, MCS1 — –91.0 — 802.11ax, HE20, MCS2 — –88.0 — 802.11ax, HE20, MCS3 — –85.0 — 802.11ax, HE20, MCS4 — –82.0 — 802.11ax, HE20, MCS5 — –78.0 — 802.11ax, HE20, MCS6 — –76.0 — 802.11ax, HE20, MCS7 — –74.5 — 802.11ax, HE20, MCS8 — –71.0 — 802.11ax, HE20, MCS9 — –68.0 — Table 25: Maximum RX Level Min Typ Max Rate (dBm) (dBm) (dBm) 802.11b, 1 Mbps, DSSS — 5 — 802.11b, 11 Mbps, CCK — 5 — 802.11g, 6 Mbps, OFDM — 5 — 802.11g, 54 Mbps, OFDM — 0 — 802.11n, HT20, MCS0 — 5 — 802.11n, HT20, MCS7 — 0 — 802.11n, HT40, MCS0 — 5 — 802.11n, HT40, MCS7 — 0 — 802.11ax, HE20, MCS0 — 5 — 802.11ax, HE20, MCS9 — 0 — Table 26: RX Adjacent Channel Rejection Min Typ Max Rate (dB) (dB) (dB) 802.11b, 1 Mbps, DSSS — 38 — 802.11b, 11 Mbps, CCK — 38 — 802.11g, 6 Mbps, OFDM — 33 — 802.11g, 54 Mbps, OFDM — 16 — 802.11n, HT20, MCS0 — 32 — Cont’d on next page Espressif Systems 31 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 7 RF Characteristics Table 26 – cont’d from previous page Min Typ Max Rate (dB) (dB) (dB) 802.11n, HT20, MCS7 — 17 — 802.11n, HT40, MCS0 — 24 — 802.11n, HT40, MCS7 — 13 — 802.11ax, HE20, MCS0 — 37 — 802.11ax, HE20, MCS9 — 13 — 7.2 Bluetooth 5 (LE) Radio Table 27: Bluetooth LE RF Characteristics Name Description Center frequency range of operating channel 2402 ~ 2480 MHz RF transmit power range –15 ~ 20 dBm 7.2.1 Bluetooth LE RF Transmitter (TX) Characteristics Table 28: Bluetooth LE - Transmitter Characteristics - 1 Mbps Parameter Description Min Typ Max Unit Carrier frequency offset and drift Max. |f n | n=0, 1, 2, 3, ...k — 10.9 — kHz Max. |f 0 − f n | n=2, 3, 4, ...k — 3.5 — kHz Max. |f n − f n−5 | n=6, 7, 8, ...k — 2.4 — kHz |f 1 − f 0 | — 2.7 — kHz Modulation characteristics ∆ F 1 avg — 250.0 — kHz Min. ∆ F 2 max (for at least 99.9% of all ∆ F 2 max ) — 243.0 — kHz ∆ F 2 avg /∆ F 1 avg — 0.88 — — In-band emissions ± 2 MHz offset — –27 — dBm ± 3 MHz offset — –36 — dBm > ± 3 MHz offset — –42 — dBm Table 29: Bluetooth LE - Transmitter Characteristics - 2 Mbps Parameter Description Min Typ Max Unit Carrier frequency offset and drift Max. |f n | n=0, 1, 2, 3, ...k — 9.4 — kHz Max. |f 0 − f n | n=2, 3, 4, ...k — 3.7 — kHz Max. |f n − f n−5 | n=6, 7, 8, ...k — 1.1 — kHz |f 1 − f 0 | — 3.3 — kHz Modulation characteristics ∆ F 1 avg — 499.4 — kHz Cont’d on next page Espressif Systems 32 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 7 RF Characteristics Table 29 – cont’d from previous page Parameter Description Min Typ Max Unit Min. ∆ F 2 max (for at least 99.9% of all ∆ F 2 max ) — 532.0 — kHz ∆ F 2 avg /∆ F 1 avg — 0.95 — — In-band emissions ± 4 MHz offset — –41 — dBm ± 5 MHz offset — –44 — dBm > ± 5 MHz offset — –45 — dBm Table 30: Bluetooth LE - Transmitter Characteristics - 125 Kbps Parameter Description Min Typ Max Unit Carrier frequency offset and drift Max. |f n | n=0, 1, 2, 3, ...k — 10.1 — kHz Max. |f 0 − f n | n=1, 2, 3, ...k — 2.1 — kHz |f 0 − f 3 | — 1.2 — kHz Max. |f n − f n−3 | n=7, 8, 9, ...k — 0.7 — kHz Modulation characteristics ∆ F 1 avg — 253.1 — kHz Min. ∆ F 1 max (for at least 99.9% of all ∆ F 1 max ) — 270.5 — kHz In-band emissions ± 2 MHz offset — –27 — dBm ± 3 MHz offset — –38 — dBm > ± 3 MHz offset — –43 — dBm Table 31: Bluetooth LE - Transmitter Characteristics - 500 Kbps Parameter Description Min Typ Max Unit Carrier frequency offset and drift Max. |f n | n=0, 1, 2, 3, ...k — 10.2 — kHz Max. |f 0 − f n | n=1, 2, 3, ...k — 1.2 — kHz |f 0 − f 3 | — 0.6 — kHz Max. |f n − f n−3 | n=7, 8, 9, ...k — 1.8 — kHz Modulation characteristics ∆ F 2 avg — 223.4 — kHz Min. ∆ F 2 max (for at least 99.9% of all ∆ F 2 max ) — 243.5 — kHz In-band emissions ± 2 MHz offset — –27 — dBm ± 3 MHz offset — –37 — dBm > ± 3 MHz offset — 43 — dBm 7.2.2 Bluetooth LE RF Receiver (RX) Characteristics Table 32: Bluetooth LE - Receiver Characteristics - 1 Mbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –98.0 — dBm Maximum received signal @30.8% PER — — 8 — dBm Cont’d on next page Espressif Systems 33 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 7 RF Characteristics Table 32 – cont’d from previous page Parameter Description Min Typ Max Unit C/I and receiver selectivity performance Co-channel F = F0 MHz — 7 — dB Adjacent channel F = F0 + 1 MHz — –2 — dB F = F0 – 1 MHz — –3 — dB F = F0 + 2 MHz — –34 — dB F = F0 – 2 MHz — –27 — dB F = F0 + 3 MHz — –33 — dB F = F0 – 3 MHz — –40 — dB F ≥ F0 + 4 MHz — –27 — dB F ≤ F0 – 4 MHz — –53 — dB Image frequency — — –35 — dB Adjacent channel to image frequency F = F image + 1 MHz — –34 — dB F = F image – 1 MHz — –33 — dB 30 MHz ~ 2000 MHz — –20 — dBm Out-of-band blocking performance 2003 MHz ~ 2399 MHz — –25 — dBm 2484 MHz ~ 2997 MHz — –25 — dBm 3000 MHz ~ 12.75 GHz — –10 — dBm Intermodulation — — –32 — dBm Table 33: Bluetooth LE - Receiver Characteristics - 2 Mbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –94.0 — dBm Maximum received signal @30.8% PER — — 8 — dBm C/I and receiver selectivity performance Co-channel F = F0 MHz — 9 — dB Adjacent channel F = F0 + 2 MHz — –7 — dB F = F0 – 2 MHz — –6 — dB F = F0 + 4 MHz — –21 — dB F = F0 – 4 MHz — –27 — dB F = F0 + 6 MHz — –38 — dB F = F0 – 6 MHz — –41 — dB F ≥ F0 + 8 MHz — –46 — dB F ≤ F0 – 8 MHz — –46 — dB Image frequency — — –21 — dB Adjacent channel to image frequency F = F image + 2 MHz — –38 — dB F = F image – 2 MHz — –7 — dB 30 MHz ~ 2000 MHz — –25 — dBm Out-of-band blocking performance 2003 MHz ~ 2399 MHz — –25 — dBm 2484 MHz ~ 2997 MHz — –25 — dBm 3000 MHz ~ 12.75 GHz — –10 — dBm Intermodulation — — –31 — dBm Espressif Systems 34 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 7 RF Characteristics Table 34: Bluetooth LE - Receiver Characteristics - 125 Kbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –105.0 — dBm Maximum received signal @30.8% PER — — 8 — dBm C/I and receiver selectivity performance Co-channel F = F0 MHz — 4 — dB Adjacent channel F = F0 + 1 MHz — –2 — dB F = F0 – 1 MHz — –3 — dB F = F0 + 2 MHz — –33 — dB F = F0 – 2 MHz — –36 — dB F = F0 + 3 MHz — –35 — dB F = F0 – 3 MHz — –50 — dB F ≥ F0 + 4 MHz — –31 — dB F ≤ F0 – 4 MHz — –50 — dB Image frequency — — –31 — dB Adjacent channel to image frequency F = F image + 1 MHz — –36 — dB F = F image – 1 MHz — –35 — dB Table 35: Bluetooth LE - Receiver Characteristics - 500 Kbps Parameter Description Min Typ Max Unit Sensitivity @30.8% PER — — –102.0 — dBm Maximum received signal @30.8% PER — — 8 — dBm C/I and receiver selectivity performance Co-channel F = F0 MHz — 4 — dB Adjacent channel F = F0 + 1 MHz — –4 — dB F = F0 – 1 MHz — –3 — dB F = F0 + 2 MHz — –32 — dB F = F0 – 2 MHz — –36 — dB F = F0 + 3 MHz — –35 — dB F = F0 – 3 MHz — –50 — dB F ≥ F0 + 4 MHz — –29 — dB F ≤ F0 – 4 MHz — –50 — dB Image frequency — — –29 — dB Adjacent channel to image frequency F = F image + 1 MHz — –36 — dB F = F image – 1 MHz — –35 — dB Espressif Systems 35 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 8 Module Schematics 8 Module Schematics This is the reference design of the module. 5 5 4 4 3 3 2 2 1 1 D D C C B B A A The values of L3, C5, C11, L2 and C12 vary with the actual PCB board. The values of C1 and C4 vary with the selection of the crystal. The value of R4 varies with the actual PCB board. The initial value is suggested to be 24 nH. ESP32-C61-WROOM-1(Pin-out) NC: No component. 50 ohm Impedance Control For modules with embedded PSRAM, SPICS1 is connected to CS pin of the embedded PSRAM and can not be used for other funtions. GND GND GND GND GND GNDGND GND GND GND GNDGND GND GND GND GND VDD_SPI VDD33 VDD33 VDD33 GND VDD33 VDD33 VDD_SPI GND VDD33 GND GNDGND GND GND GNDGND GND Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP32-C61-WROOM-1> 1.2 A4 2 2Friday, July 18, 2025 Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP32-C61-WROOM-1> 1.2 A4 2 2Friday, July 18, 2025 Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP32-C61-WROOM-1> 1.2 A4 2 2Friday, July 18, 2025 C12 TBD C6 10uF C3 1uF C4 TBD R4 TBD D2 ESD(NC) R8 10K(NC) D1 ESD C10 0.1uF R3 499 R15 0 C17 1uF ANT1 PCB_ANT 1 2 R13 0 C5 TBD L1 2.0nH C15 0.1uF U1 ESP32-C61 VDDA3 2 VDDA4 3 MTMS 9 SPICS1 19 MTDI 10 USB_D- 28 MTDO 12 MTCK 11 SPICS0 20 VDDPST1 5 GPIO2 8 USB_D+ 29 GPIO7 36 XTAL_32K_P 6 XTAL_32K_N 7 CHIP_PU 4 SPICLK 26 SPIHD 25 VDDPST2 21 GPIO8 31 GPIO9 32 U0RXD 33 XTAL_N 38 XTAL_P 39 VDDA1 37 ANT_2G 1 GND 41 SPIWP 23 VDD_SPI 24 SPID 27 U0TXD 34 VDDA2 40 SPIQ 22 GPIO29 35 GPIO24 30 SDIO_CMD 13 SDIO_CLK 14 SDIO_DATA0 15 SDIO_DATA1 16 SDIO_DATA2 17 SDIO_DATA3 18 C143.0pF U2 FLASH VDD 8 GND 4 /CS 1 CLK 6 /HOLD 7 /WP 3 DO 2 DI 5 C11 TBD L2 TBD C7 1uF C1 TBD R16 0 C8 0.1uF ESP32-C61-WROOM-1 GND 1 3V3 2 EN 3 IO4 4 IO5 5 IO6 6 IO7 7 IO0 8 IO1 9 IO8 10 IO29 11 NC/IO14 12 IO12 13 IO13 14 GND 28 IO2 27 IO3 26 TX0 25 RX0 24 IO24 23 NC 22 IO23 21 IO22 20 IO28 19 IO27 18 IO26 17 IO25 16 IO9 15 EPAD 29 R14 0 R10 0 L3 TBD C16 0.1uF Y1 40MHz XIN 1 GND 2 XOUT 3 GND 4 C9 0.1uF C2 10nF C13 3.0pF ANT_2G GPIO8 GPIO9 CHIP_PU GPIO0 GPIO1 CHIP_PU GPIO2 GPIO0 GPIO1 NC_GPIO14 SPICS0 GPIO4 GPIO5 GPIO6 GPIO8 GPIO12 GPIO13 GPIO9 U0RXD U0TXD GPIO2 GPIO3 SPICLK SPICS0 SPIHD SPID SPIWP SPIQ GPIO23 U0TXD U0RXD GPIO29 GPIO7 GPIO3 GPIO4 GPIO6 GPIO26 GPIO27 GPIO28 GPIO22 GPIO23 GPIO7 GPIO25 GPIO24 NC_GPIO14 GPIO29 GPIO27 GPIO28 GPIO26 GPIO25 GPIO22 GPIO13 GPIO24 GPIO12 SPIHD SPICLK SPID SPIQ SPIWP RF_ANT GPIO5 Figure 7: ESP32-C61-WROOM-1 Schematics Espressif Systems 36 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 8 Module Schematics 5 5 4 4 3 3 2 2 1 1 D D C C B B A A The values of L3, C18, C11, L2 and C12 vary with the actual PCB board. The values of C1 and C4 vary with the selection of the crystal. The value of R4 varies with the actual PCB board. The initial value is suggested to be 24 nH. ESP32-C61-WROOM-1U(Pin-out) NC: No component. 50 ohm Impedance Control For modules with embedded PSRAM, SPICS1 is connected to CS pin of the embedded PSRAM and can not be used for other funtions. GND GND GND GND GND GND GNDGND GND GND GND GNDGND GND GND GND GND VDD_SPI VDD33 VDD33 VDD33 GND VDD33 GND GND GNDGND VDD_SPI GND VDD33 GND VDD33 GND GND GND GND GND Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP32-C61-WROOM-1U> 1.3 A4 2 2Wednesday, March 25, 2026 Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP32-C61-WROOM-1U> 1.3 A4 2 2Wednesday, March 25, 2026 Title Size Page Name Rev Date: Sheet of Confidential and Proprietary <02_ESP32-C61-WROOM-1U> 1.3 A4 2 2Wednesday, March 25, 2026 C11 TBD C6 10uF R2 TBD(NC) C12 TBD L3 TBD R8 10K(NC) C4 TBD C3 1uF R15 0 R3 499 D1 ESD C10 0.1uF D2 ESD(NC) R4 TBD R13 0 C17 1uF C5 3.0pF L1 2.0nH C13 3.0pF U2 FLASH VDD 8 GND 4 /CS 1 CLK 6 /HOLD 7 /WP 3 DO 2 DI 5 C18 TBD C7 1uF C15 0.1uF L2 TBD ESP32-C61-WROOM-1U GND 1 3V3 2 EN 3 IO4 4 IO5 5 IO6 6 IO7 7 IO0 8 IO1 9 IO8 10 IO29 11 NC/IO14 12 IO12 13 IO13 14 GND 28 IO2 27 IO3 26 TX0 25 RX0 24 IO24 23 NC 22 IO23 21 IO22 20 IO28 19 IO27 18 IO26 17 IO25 16 IO9 15 EPAD 29 GND 30 ANT2 31 GND 32 C8 0.1uF R16 0 C1 TBD U1 ESP32-C61 VDDA3 2 VDDA4 3 MTMS 9 SPICS1 19 MTDI 10 USB_D- 28 MTDO 12 MTCK 11 SPICS0 20 VDDPST1 5 GPIO2 8 USB_D+ 29 GPIO7 36 XTAL_32K_P 6 XTAL_32K_N 7 CHIP_PU 4 SPICLK 26 SPIHD 25 VDDPST2 21 GPIO8 31 GPIO9 32 U0RXD 33 XTAL_N 38 XTAL_P 39 VDDA1 37 ANT_2G 1 GND 41 SPIWP 23 VDD_SPI 24 SPID 27 U0TXD 34 VDDA2 40 SPIQ 22 GPIO29 35 GPIO24 30 SDIO_CMD 13 SDIO_CLK 14 SDIO_DATA0 15 SDIO_DATA1 16 SDIO_DATA2 17 SDIO_DATA3 18 R1 0 R14 0 ANT1 CONN R10 0 C9 0.1uF Y1 40MHz XIN 1 GND 2 XOUT 3 GND 4 C16 0.1uF C2 10nF C143.0pF ANT_2G GPIO9 CHIP_PU GPIO0 GPIO1 CHIP_PU GPIO2 GPIO0 GPIO1 NC_GPIO14 SPICS0 GPIO4 GPIO5 GPIO6 GPIO8 GPIO12 GPIO13 GPIO9 U0RXD U0TXD GPIO2 GPIO3 SPICLK SPICS0 SPIHD SPID SPIWP SPIQ GPIO23 U0TXD U0RXD ANT2 ANT1 ANT2 GPIO29 GPIO7 GPIO3 GPIO4 GPIO6 GPIO26 GPIO27 GPIO28 GPIO22 GPIO23 GPIO7 GPIO25 GPIO24 NC_GPIO14 GPIO29 GPIO27 GPIO28 GPIO26 GPIO25 GPIO22 GPIO13 GPIO24 GPIO12 SPIHD SPICLK SPID SPIQ SPIWP GPIO5 GPIO8 Figure 8: ESP32-C61-WROOM-1U Schematics Espressif Systems 37 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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, and UART interface). 5 5 4 4 3 3 2 2 1 1 D D C C B B A A NC: No component. X1: ESR = Max. 70 KΩ GND GND GND GND GND GND GND GND GND GND VDD33 VDD33 GND VDD33 GND C5 12pF(NC) SW1 C2 0.1uF R8 10K R7 0 R2 0 C3 TBD X1 32.768KHz(NC) 1 1 2 2 R4 0(NC) R5 NC C1 22uF C8 TBD U1 ESP32-C61-WROOM-1 GND 1 3V3 2 EN 3 IO4 4 IO5 5 IO6 6 IO7 7 IO0 8 IO1 9 IO8 10 IO29 11 NC/IO14 12 IO12 13 IO13 14 GND 28 IO2 27 IO3 26 TX0 25 RX0 24 IO24 23 NC 22 IO23 21 IO22 20 IO28 19 IO27 18 IO26 17 IO25 16 IO9 15 EPAD 29 JP1 UART 1 1 2 2 3 3 4 4 R1 TBD C4 0.1uF JP2 Boot Option 1 1 2 2 R6 0 R3 0(NC) JP3 USB 1 1 2 2 C7 TBD C6 12pF(NC) EN DEBUG_TX0 DEBUG_RX0 IO6 IO7 USB_D- USB_D+ IO2 IO3 IO4 IO5 IO9 EN IO12 IO13 IO24 IO23 IO22 IO8 IO0 IO1 IO28 IO29 NC_IO14 IO27 IO26 IO25 Figure 9: ESP32-C61-WROOM-1 Peripheral Schematics 5 5 4 4 3 3 2 2 1 1 D D C C B B A A NC: No component. X1: ESR = Max. 70 KΩ Single-ended 50ohm GND GND GND GND GND GND GND GND GND GND VDD33 VDD33 GND VDD33 GND GND GND GND C2 0.1uF SW1 C5 12pF(NC) R8 10K L1 TBD R2 0 R7 0 C10 TBD C3 TBD X1 32.768KHz(NC) 1 1 2 2 R5 NC R4 0(NC) C1 22uF R1 TBD JP1 UART 1 1 2 2 3 3 4 4 C8 TBD U1 ESP32-C61-WROOM-1U GND 1 3V3 2 EN 3 IO4 4 IO5 5 IO6 6 IO7 7 IO0 8 IO1 9 IO8 10 IO29 11 NC/IO14 12 IO12 13 IO13 14 GND 28 IO2 27 IO3 26 TX0 25 RX0 24 IO24 23 NC 22 IO23 21 IO22 20 IO28 19 IO27 18 IO26 17 IO25 16 IO9 15 EPAD 29 GND 30 ANT2 31 GND 32 C9 TBD C4 0.1uF JP2 Boot Option 1 1 2 2 R3 0(NC) R6 0 JP3 USB 1 1 2 2 C6 12pF(NC) C7 TBD EN DEBUG_TX0 DEBUG_RX0 IO6 IO7 USB_D- USB_D+ IO2 IO3 IO4 IO5 IO9 EN IO12 IO13 IO24 IO23 IO22 IO8 IO0 IO1 IO28 IO29 NC_IO14 IO27 IO26 IO25 ANT2 RF_ANT2 Figure 10: ESP32-C61-WROOM-1U Peripheral Schematics Espressif Systems 38 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 9 Peripheral Schematics • If an external antenna ANT2 is used, it is recommended to reserve an RF circuit as shown in the figure above. By default, ESP32-C61-WROOM-1U uses ANT1, and ANT2 is disabled. To use ANT2, please contact us. • 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 ESP32-C61 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 ESP32-C61’s power-up and reset sequence timing diagram, please refer to ESP32-C61 Series Datasheet > Section Power Supply. • UART0 is used to download firmware and log output. When using the AT firmware, please note that the UART GPIO is already configured . It is recommended to use the default configuration. Espressif Systems 39 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 10 Physical Dimensions 10 Physical Dimensions 10.1 Module Dimensions 0.8 28 x 0.85 28 x 0.9 3.1±0.15 Unit: mm 1.27 0.45 3.3 12.29 7.5 0.45 1.27 28 x 0.9 17.6 28 x 0.45 1.05 28 x Ø0.55 25.5±0.2 1.5 16.51 18±0.2 15.8 6 Ø0.5 1 0.8 3.3 0.8 Top View Side View Bottom View 1.5 1.27 16.51 31 x 0.9 Top View Bottom View 18±0.2 31 x 0.45 31 x 0.85 0.45 3.3 10.75 15.65 17.5 0.8 Side View 31 x 0.9 19.2±0.2 31 x Ø0.55 0.8 1.08 0.65 2.46 3 3.2±0.15 Unit: mm 13.1 Ø0.5 7.5 12.29 0.8 3.3 5 1.27 0.45 Figure 11: ESP32-C61-WROOM-1 Physical Dimensions 1.5 1.27 16.51 31 x 0.9 Top View Bottom View 18±0.2 31 x 0.45 31 x 0.85 0.45 3.3 10.75 15.65 17.5 0.8 Side View 31 x 0.9 19.2±0.2 31 x Ø0.55 0.8 1.08 0.65 2.46 3 3.2±0.15 Unit: mm 13.1 Ø0.5 7.5 12.29 0.8 3.3 5 1.27 0.45 1.27 5 1.27 Figure 12: ESP32-C61-WROOM-1U Physical Dimensions Note: For information about tape, reel, and product marking, please refer to ESP32-C61 Chip Packaging Information. Espressif Systems 40 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 10 Physical Dimensions 10.2 Dimensions of External Antenna Connector ESP32-C61-WROOM-1U uses the first generation external antenna connector as shown in Figure 13 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 13: Dimensions of External Antenna Connector Espressif Systems 41 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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 14 ESP32-C61-WROOM-1 Recommended PCB Land Pattern and Figure 15 ESP32-C61-WROOM-1U Recommended PCB Land Pattern. • Source files of recommended PCB land patterns to measure dimensions not covered in Figure 14 and Figure 15 . You can view the source files for ESP32-C61-WROOM-1 and ESP32-C61-WROOM-1U with Autodesk Viewer. • 3D models of ESP32-C61-WROOM-1 and ESP32-C61-WROOM-1U . Please make sure that you download the 3D model file in .STEP format (beware that some browsers might add .txt). Antenna Area 1 28 14 15 18 6 7.49 1.27 25.5 28x1.5 28x0.9 1.5 16.51 0.5 17.5 0.8 3.3 3.3 7.5 Unit: mm Copper Via for thermal pad 0.8 0.45 0.45 12.29 29 Figure 14: ESP32-C61-WROOM-1 Recommended PCB Land Pattern Espressif Systems 42 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 11 PCB Layout Recommendations 1 19.2 14 18 15 1.5 31 x1.5 0.5 0.5 3.3 0.8 0.8 7.5 1.27 3.3 28 31 x0.9 Unit: mm Via for thermal pad Copper 12.29 17.5 16.51 1.19 Recommend 50 Ω impedance control for ANT2 pad if used 323130 29 0.45 0.45 5 1.27 Figure 15: ESP32-C61-WROOM-1U 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 ESP32-C61 Hardware Design Guidelines > Section Positioning a Module on a Base Board. Espressif Systems 43 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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 16: Reflow Profile Espressif Systems 44 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 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 45 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 Related Documentation and Resources Related Documentation and Resources Related Documentation • ESP32-C61 Series Datasheet – Specifications of the ESP32-C61 hardware. • ESP32-C61 Technical Reference Manual – Detailed information on how to use the ESP32-C61 memory and pe- ripherals. • ESP32-C61 Hardware Design Guidelines – Guidelines on how to integrate the ESP32-C61 into your hardware product. • Certificates https://espressif.com/en/support/documents/certificates • ESP32-C61 Product/Process Change Notifications (PCN) https://espressif.com/en/support/documents/pcns?keys=ESP32-C61 • ESP32-C61 Advisories – Information on security, bugs, compatibility, component reliability. https://espressif.com/en/support/documents/advisories?keys=ESP32-C61 • Documentation Updates and Update Notification Subscription https://espressif.com/en/support/download/documents Developer Zone • ESP-IDF Programming Guide for ESP32-C61 – 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 • ESP32-C61 Series SoCs – Browse through all ESP32-C61 SoCs. https://espressif.com/en/products/socs?id=ESP32-C61 • ESP32-C61 Series Modules – Browse through all ESP32-C61-based modules. https://espressif.com/en/products/modules?id=ESP32-C61 • ESP32-C61 Series DevKits – Browse through all ESP32-C61-based devkits. https://espressif.com/en/products/devkits?id=ESP32-C61 • 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 46 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 Revision History Revision History Date Version Release notes 2026-03-26 v1.1 Updated ESP32-C61-WROOM-1U Schematics of Chapter 8 Module Schemat- ics 2025-12-30 v1.0 Official release 2025-09-09 v0.6 • Updated Chapter 8 Module Schematics • Updated Figure 6 Visualization of Timing Parameters for the Strapping Pins 2025-05-30 v0.5 First release Espressif Systems 47 Submit Documentation Feedback ESP32-C61-WROOM-1 & WROOM-1U Datasheet v1.1 Disclaimer and Copyright Notice Information in this document, including URL references, is subject to change without notice. ALL THIRD PARTY’S INFORMATION IN THIS DOCUMENT IS PROVIDED AS IS WITH NO WARRANTIES TO ITS AUTHENTICITY AND ACCURACY. NO WARRANTY IS PROVIDED TO THIS DOCUMENT FOR ITS MERCHANTABILITY, NON-INFRINGEMENT, FITNESS FOR ANY PARTICULAR PURPOSE, NOR DOES 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 document 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 © 2026 Espressif Systems (Shanghai) Co., Ltd. All rights reserved. www.espressif.com