WBR3S Module Datasheet

Last Updated on : 2024-06-14 03:15:58download

WBR3S is a low-power embedded Wi-Fi and Bluetooth module that Tuya has developed. It consists of a highly integrated RF chip (RTL8720CS-VA1) and several peripheral components, with an embedded Wi-Fi network protocol stack, Bluetooth network protocol, and robust library functions.


WBR3S is embedded with a low-power 32-bit CPU, 512 KB static random-access memory (SRAM), and 4 MB flash memory, and has extensive peripherals.

WBR3S is an RTOS platform that integrates all function libraries of the Wi-Fi MAC and TCP/IP protocols. You can develop embedded Wi-Fi products as required.


  • Embedded low-power 32-bit CPU, which can also function as an application processor
  • Dominant frequency: Up to 200 MHz
  • Operating voltage: 3.0 V to 3.6 V
  • Peripherals: 8 GPIOs, 1 UART, and 1 ADC
  • Wi-Fi connectivity
    • 802.11a/b/g/n 1T1R, 2.4 GHz
    • Channels 1 to 14 at 2.4 GHz
    • Support WEP/WPA/WPA2/WPA2 PSK (AES) WPA3 security mode
    • Up to +17 dBm output power in 802.11b mode
    • STA, AP, and STA+AP working modes
    • Smart and AP network configuration modes for Android and iOS devices
    • Onboard PCB antenna with a gain of 1.7dBi in 2.4G band
    • Operating temperature: –20°C to +85°C
  • Bluetooth connectivity
    • Support Bluetooth V5.0
    • Up to +6dBm TX power
    • Onboard PCB antenna with a gain of 1.7dBi in 2.4G frequency band, sharing the same antenna with Wi-Fi
    • Operating temperature: –20°C to +85°C


  • Intelligent building
  • Smart household and home appliances
  • Smart socket and light
  • Industrial wireless control
  • Baby monitor
  • Network camera
  • Intelligent bus

Module interfaces

Dimensions and footprint

WBR3S has two lines of pins with a pin spacing of 2±0.1 mm.

The WBR3S dimensions (H x W x L) are 2.8±0.15 mm x 16±0.3 mm x 24±0.3 mm.

The front and rear views of WBR3S:

WBR3S Module DatasheetWBR3S Module Datasheet

Note: The common outline tolerance is ±0.35 mm. The tolerance of parts that involve plug-in assembly is ±0.1 mm. The tolerance of a 1-mm-thick PCB is ±0.1 mm.

Pin definition

WBR3S Module Datasheet

Pin No. Symbol I/O type Function
1 RST I/O The Reset Pin
2 ADC AI 10-bit precision SAR ADC(1), the Pin PB3 of IC
3 EN I Module enabling pin, which is connected to 3.3 V for normal use, refer to the CHIP_EN of IC
4 PA15 I/O GPIO, The pin PA15 of IC
5 PA13 P PWM Pin, The pin PA13 of IC
6 PA12 I/O PWM Pin, The pin PA12 of IC
7 PA26 I/O PWM Pin, The pin PA26 of IC
8 VCC P Power supply pin (3.3 V)
9 GND P Power supply reference ground pin
10 PA25 O GPIO, The pin PA25 of IC
11 LOG_TX O UART0_TXD (used to display the module internal information)
12 PB20 I/O GPIO, The pin PB20 of IC
13 PB21 I/O PWM Pin, The pin PB21 of IC
14 PA28 I/O PWM Pin, The pin PA28 of IC
15 RXD/PB2 I/O UART0_RXD (2), refer to the PB2 of IC
16 TXD/PB1 I/O UART0_TXD(2), refer to the PB1 of IC


  • P indicates power supply pins, I/O indicates input/output pins, and AI indicates analog input pins.
  • (1): This pin can only function as an ADC input and not a common I/O. If this pin is not used, it must be disconnected. When this pin is used as the ADC input, the input voltage range is 0 V to 1.0 V.
  • (2): UART0 is a user-side serial interface, which generates information when the module is powered on and starts.

Test pin definition

Pin No. Symbol I/O type Function
- TEST I Used for the module production test

Note: Test pins are not recommended.

Electrical Parameters

Absolute Electrical Parameters

Parameter Description Minimum Value Maximum Value Unit
Ts Storage temperature -20 85
VBAT Power supply voltage 3.0 3.6 V
ESD voltage (human body model) TAMB-25℃ - 2 KV
ESD voltage (machine model) TAMB-25℃ - 0.5 KV

Normal electrical conditions

Parameter Description Minimum Value Typical Value Maximum Value Unit
Ta Operating temperature -20 - 85
VBAT Power supply voltage 3.0 3.3 3.6 V
VIL I/O low-level input -0.3 - VCC*0.25 V
VIH I/O high-level input VCC*0.75 - VCC V
VOL I/O low-level output - - VCC*0.1 V
VOH I/O high-level output VCC*0.8 - VCC V
Imax I/O drive current - - 12 mA

Current during constant transmission and receiving

2.4G transmission and receive

Working status Mode Rate TX power/Receive Typical Value Unit
TX 11b 11Mbps +18dBm 250 mA
TX 11g 54Mbps +17dBm 180 mA
TX 11n-HT20 MCS7 +16dBm 170 mA
TX 11n-HT40 MCS7 +16dBm 150 mA
RX 11b 11Mbps Receiving 70 mA
RX 11g 54Mbps Receiving 72 mA
RX 11n-HT20 MCS7 Receiving 70 mA
RX 11n-HT40 MCS7 Receiving 73 mA

Operating current

Working mode Working status (Ta = 25°C) Average value Maximum value (Typical value) Unit
EZ The module is in EZ mode, and the Wi-Fi indicator blinks quickly. 57 184 mA
AP The module is in AP mode, and the Wi-Fi indicator blinks slowly 203 392 mA
Connected The module is connected to the network, and the Wi-Fi indicator is steady on. 55 98 mA
Disconnected The module is disconnected from the network, and the Wi-Fi indicator is steady off. 53 59 mA

RF features

Basic RF features

Parameter Description
Frequency band 2.412~2.484GHz
Wi-Fi standard IEEE 802.11b/g/n (Channels 1 to 14
Data transmission rate 802.11b: 1, 2, 5.5, or 11 (Mbit/s);802.11g: 6, 9, 12, 18, 24, 36, 48, or 54 (Mbit/s);802.11n: HT20 MCS0 to MCS7;802.11n: HT40 MCS0 to MCS7
Antenna type PCB antenna with a gain of 1.7 dBi at 2.4 GHz

TX prformance

Performance during constant transmission at 2.4 GHz

Parameter Minimum Value Typical Value Maximum Value Unit
Average RF output power, 802.11b CCK mode 11M - 17 - dBm
Average RF output power, 802.11g OFDM Mode 54M - 16 - dBm
Average RF output power, 802.11n HT20 Mode MCS7 - 15 - dBm
Average RF output power, 802.11n HT40 Mode MCS7 - 14 - dBm
Frequency error -10 - 10 ppm

RX performance

RX sensitivity

Parameter Minimum Value Typical Value Maximum Value Unit
PER<8%, 802.11b DSSS Mode 11M - -91 - dBm
PER<10%, 802.11a/g OFDM Mode 54 M - -75 - dBm
PER<10%, 802.11n OFDM Mode HT20-MCS7 - -72 - dBm


###Antenna Type
WBR3S uses an onboard PCB antenna.

Antenna interference reduction

To ensure optimal Wi-Fi performance when the Wi-Fi module uses an onboard PCB antenna, it is recommended that the antenna be at least 15 mm away from other metal parts.

To prevent adverse impact on the antenna radiation performance, avoid copper or traces along the antenna area on the PCB. Ensure that there are no substrate media above or below the antenna and that copper is at a certain distance away from the antenna to maximize the antenna radiation performance.

WBR3S Module Datasheet

GPIO pin processing

Module individual pin (PA15 PA12, PA13, PA25, PA28, PA26) before the chip didn’t completely work. It will be an instantaneous high-level pulse, But everything is ok after the chip work. For these pins, if used directly as a driver of light source or relay, the following reference processing can be done to avoid the effect of instant burr during the power on.

Pull-down a 1K resistor at the output port of the pin, then series a diode, and the VOLTAGE of GPIO will drop to about 2.7V after passing the diode. The red frame represents the original drive tube on the customer bottom plate, diode D1 and drops 1K needs to be added.

If the lamp class is driven directly, then the 10K resistor is pulled down from the gate of the MOS tube. If the lamp class is not driven directly and the PWM signal is not sent until the module is formally set up, then there is no need to add the pull-down resistor and diode.

If the relay is driven, the diode can be replaced with 0 ohm according to the actual situation.

WBR3S Module Datasheet

Packaging information and production instructions

Mechanical dimensions

The mechanical dimensions of PCB: 16±0.35 mm (W)×24±0.3 mm (L) ×0.8±0.1 mm (H).
WBR3S Module Datasheet

Side view

WBR3S Module Datasheet

Note: The default dimensional tolerance is ±0.3 mm. If you have specific requirements on key dimensions, specify them in the module datasheet after communication.

Schematic diargam of footprint

WBR3S Module Datasheet

Diagram of PCB footprint-Pin header

Optionally, WBR3S may be mounted with the SMT.

Diagram of PCB footprint-SMT

WBR3S Module Datasheet

Production instructions

  1. The Tuya SMT module should be mounted by the SMT device. After being unpacked, it should be soldered within 24 hours. Otherwise, it should be put into the drying cupboard where the RH is not greater than 10%; or it needs to be packaged under vacuum again and the exposure time needs to be recorded (the total exposure time cannot exceed 168 hours).
    • SMT devices:
      • Mounter
      • SPI
      • Reflow soldering machine
      • Thermal profiler
      • Automated optical inspection (AOI) equipment
    • Baking devices:
      • Cabinet oven
      • Anti-electrostatic and heat-resistant trays
      • Anti-electrostatic and heat-resistant gloves
  2. Storage conditions for a delivered module:
    • The moisture-proof bag must be placed in an environment where the temperature is below 40°C and the relative humidity is lower than 90%.

    • The shelf life of a dry-packaged product is 12 months from the date when the product is packaged and sealed.

    • There is a humidity indicator card (HIC) in the packaging bag.

      WBR3S Module Datasheet

  3. The module needs to be baked in the following cases:
    • The packaging bag is damaged before unpacking.
    • There is no HIC in the packaging bag.
    • After unpacking, circles of 10% and above on the HIC become pink.
    • The total exposure time has lasted for over 168 hours since unpacking.
    • More than 12 months have passed since the sealing of the bag.
  4. Baking settings:
    • Temperature: 40°C and ≤ 5% RH for reel package and 125°C and ≤5% RH for tray package (please use the heat-resistant tray rather than plastic container)
    • Time: 168 hours for reel package and 12 hours for tray package
    • Alarm temperature: 50°C for reel package and 135°C for tray package
    • Production-ready temperature after natural cooling: < 36°C
    • Re-baking situation: If a module remains unused for over 168 hours after being baked, it needs to be baked again.
    • If a batch of modules is not baked within 168 hours, do not use the wave soldering to solder them. Because these modules are Level-3 moisture-sensitive devices, they are very likely to get damp when exposed beyond the allowable time. In this case, if they are soldered at high temperatures, it may result in device failure or poor soldering.
  5. In the whole production process, take electrostatic discharge (ESD) protective measures.
  6. To guarantee the passing rate, it is recommended that you use the SPI and AOI to monitor the quality of solder paste printing and mounting.

Recommended oven temperature curve

Set oven temperatures according to the following temperature curve of reflow soldering. The peak temperature is 245°C.

WBR3S Module Datasheet

  • A: Temperature axis

  • B: Time axis

  • C: Liquidus temperature: 217 to 220°C

  • D: Ramp-up slope: 1 to 3°C/s

  • E: Duration of constant temperature: 60 to 120s; the range of constant temperature: 150 to 200°C

  • F: Duration above the liquidus: 50 to 70s

  • G: Peak temperature: 235 to 245°C

  • H: Ramp-down slope: 1 to 4°C/s

    Note: The above curve is just an example of the solder paste SAC305. For more details about other solder pastes, please refer to Recommended oven temperature curve in the solder paste specifications.

Storage conditions

WBR3S Module Datasheet

MOQ and Packing Information

Product model MOQ Packing method Number of modules per reel Number of reels per carton
WBR3S 3600 Tape reel 900 4

Appendix: Statement

FCC Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate this device.

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Note: This device has been tested and found to comply with the limits for a Class B digital device, according to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This device generates, uses, and can radiate radio frequency energy and, if not installed and used following the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation.

If this device does cause harmful interference to radio or television reception, which can be determined by turning the device off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

  • Reorient or relocate the receiving antenna.
  • Increase the separation between the device and receiver.
  • Connect the device into an outlet on a circuit different from that to which the receiver is connected.
  • Consult the dealer or an experienced radio/TV technician for help.

Radiation Exposure Statement

This device complies with FCC radiation exposure limits set forth for an uncontrolled rolled environment. This device should be installed and operated with a minimum distance of 20cm between the radiator and your body.

Important Note

This radio module must not be installed to co-locate and operating simultaneously with other radios in the host system except following FCC multi-transmitter product procedures. Additional testing and device authorization may be required to operate simultaneously with other radios.

The availability of some specific channels and/or operational frequency bands are country dependent and are firmware programmed at the factory to match the intended destination. The firmware setting is not accessible by the end-user.

The host product manufacturer is responsible for compliance with any other FCC rules that apply to the host not covered by the modular transmitter grant of certification. The final host product still requires Part 15 Subpart B compliance testing with the modular transmitter installed.

The end-user manual shall include all required regulatory information/warnings as shown in this manual, including “This product must be installed and operated with a minimum distance of 20 cm between the radiator and user body”.

This device has got an FCC ID: 2ANDL-WBR3S. The end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID: 2ANDL-WBR3S”.

This device is intended only for OEM integrators under the following conditions:

The antenna must be installed such that 20cm is maintained between the antenna and users, and the transmitter module may not be co-located with any other transmitter or antenna.

As long as the 2 conditions above are met, further transmitter tests will not be required. However, the OEM integrator is still responsible for testing their end-product for any additional compliance requirements required with this module installed.

Declaration of Conformity European Notice

WBR3S Module Datasheet

Hereby, Hangzhou Tuya Information Technology Co., Ltd declares that this module product is in compliance with essential requirements and other relevant provisions of Directive 2014/53/EU,2011/65/EU. A copy of the Declaration of conformity can be found at https://www.tuya.com.

WBR3S Module Datasheet

This product must not be disposed of as normal household waste, in accordance with the EU directive for waste electrical and electronic equipment (WEEE-2012/19/EU). Instead, it should be disposed of by returning it to the point of sale, or to a municipal recycling collection point.

The device could be used with a separation distance of 20cm to the human body.