Features #

• Built\-in low\-power 32\-bit MCU, which can also serve as an application processor\.

• Maximum operating frequency: 48 MHz\.

• Operating voltage: 3\.0 V – 3\.6 V\.

• Peripherals: 5 × PWM, 1 × I2C, 1 × UART\.

Bluetooth RF Features #

• Bluetooth 5\.0

• Data transfer rate: up to 2 Mbps

• TX output power: \+10 dBm

• RX sensitivity: \-94\.5 dBm @ Bluetooth 1 Mbps

• Built\-in hardware AES encryption $requiresspecifictesting$

• Onboard PCB antenna

• Operating temperature: \-40°C to \+85°C

Application Areas #

• Smart LED lighting

• Smart home devices

• Low\-power smart sensors

• Smart building systems

• Home automation/appliances

• Smart plugs, smart lights

• Industrial wireless control

• Baby monitors

• Smart public transportation

Dimensions and Packaging #

BT7L has two rows of pins with a pitch of 1\.5 mm\. Module dimensions: 15 ± 0\.35 mm $W$ × 16\.5 ± 0\.35 mm $L$ × 2\.85 ± 0\.15 mm $H$, with PCB thickness 1\.0 ± 0\.1 mm, as shown in the figure\. Top view of the module\.

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Bottom View of the module\.

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Pin Definition #

Note:P indicates a power supply pin, and I/O indicates an input/output pin\. If you have specific requirements for the color control of LEDs driven by PWM outputs, please contact us for further support\.

Absolute Electrical Parameters #

Operating Conditions #

Power Consumption in Operating Mode $ToBeMeasured$ #

Basic RF Characteristics #

RF Output Power #

RF Receive Sensitivity #

Antenna Type #

The BT7L module uses an on\-board PCB antenna\.

Antenna Interference Mitigation #

To ensure optimal RF performance, it is recommended to maintain a minimum distance of 15 mm between the module antenna and any metal objects\.

Users should avoid routing traces or placing copper pours in the antenna area of the host PCB, as these may adversely affect antenna performance\.

Key layout considerations include:

• Ensure that there is no PCB substrate directly beneath or above the printed antenna\.

• Keep the area surrounding the printed antenna free from metal objects and copper planes\.

• Avoid routing signal traces within the antenna keep\-out area\.

• Following these guidelines helps maximize antenna radiation efficiency and overall RF performance\.

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Mechanical Dimensions and Backside Pad Layout #

   

Front View #

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Side View #

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Note:

The default tolerance for the module outline dimensions is ±0\.35 mm, while the tolerance for critical dimensions is ±0\.1 mm\.

If the customer has specific requirements for any critical dimensions, these dimensions should be clearly defined and annotated in the specification after mutual agreement\.

The keep\-out area indicated in the figure above should not be soldered and must be kept free of any PCB traces or routing\.

Application Circuit #

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Antenna Layout Requirements #

Place the module at the edge of the main PCB\. Do not place any metal objects near the antenna area, and keep the antenna away from high\-frequency components\.

Power Supply #

$1$ A 3\.3 V power supply is recommended, with a peak current capability of at least 50 mA\.

$2$ An LDO regulator is recommended\. If a DC\-DC converter is used, it is recommended to keep the output ripple voltage below 30 mV\.

$3$ For DC\-DC power supply designs, it is recommended to reserve space for dynamic response capacitors to optimize output ripple performance when significant load variations occur\.

$4$ It is recommended to add ESD protection devices to the 3\.3 V power supply input\.

PWM Dimming Design Guidelines #

For lighting applications requiring dimming functionality, simply connect the PWM pin corresponding to the desired color channel to the control input of the downstream driver circuit\. The PWM output provides an independently controlled digital signal with 100 levels of adjustable duty cycle\. The downstream circuit may be either voltage\-driven or current\-driven\.

Connection Diagram

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LED Driver Reference Design #

The TB\-04 module requires only a 3\.3 V power supply and a simple driver circuit to implement intelligent lighting control\. Taking a single cool\-white LED channel driven by a MOSFET as an example, the reference design is shown in the figure below\.

CW\_I is the PWM output pin for the cool\-white channel of the module, Q1 is the MOSFET, and WW represents the LED\. The other four LED driver channels can be designed using the same approach as this channel\.

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Reflow Soldering Profile #

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Assembly Method #

For factory\-supplied SMD\-packaged modules, it is recommended to use SMT machines for placement\. After opening the packaging, soldering should be completed within 24 hours\.

If the modules are not used completely after opening, they should be stored in a dry cabinet with humidity not exceeding 10% RH, or re\-packaged in vacuum and the exposure time should be recorded\. The total exposure time should not exceed 168 hours\.

Storage Conditions for Factory\-Supplied Modules #

• Moisture\-proof bags must be stored at temperatures below 40°C and relative humidity below 90% RH\.

• For dry\-packaged products, the shelf life is 12 months from the date of sealing\.

• Humidity indicator cards are included inside the sealed packaging\.

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Modules Must Be Baked If Moisture Exposure Is Suspected Under Any of the Following Conditions #

• The vacuum package is found to be damaged before opening\.

• No humidity indicator card is found inside the package after opening\.

• After opening, the humidity indicator card shows that the 10% RH indicator $orhigher$ has changed to pink\.

• The total exposure time after opening exceeds 168 hours\.

• More than 12 months have elapsed since the date of the original sealed packaging\.

Baking Parameters #

• Baking Temperature:

  Reel packaging: 40°C, humidity ≤ 5% RH

  Tray packaging: 125°C, humidity ≤ 5% RH $high\text{-}temperature\text{-}resistanttraysonly;plasticblistertraysarenotsuitable$

• Baking Time:

  Reel packaging: 168 hours

  Tray packaging: 12 hours

• Alarm Temperature Setting:

  Reel packaging: 50°C

  Tray packaging: 135°C

• After baking, allow the modules to cool naturally to below 36°C before production\.

• If the modules remain unused for more than 168 hours after baking, they should be baked again before use\.

• If the exposure time exceeds 168 hours without baking, reflow soldering is not recommended for this batch of modules\. As the module is classified as an MSL 3 $MoistureSensitivityLevel3$ device, exceeding the allowable exposure time may result in moisture absorption\. High\-temperature soldering under such conditions may cause device failure or poor soldering quality\.

ESD Protection #

During the entire manufacturing process, appropriate Electrostatic Discharge $ESD$ protection measures must be implemented for the modules\.

Quality Control Recommendations #

To ensure a high production yield, it is recommended to use SPI and AOI inspection equipment to monitor solder paste printing quality and component placement quality\.

   

Recommended Reflow Profile #

Please configure the reflow oven temperature settings according to the recommended reflow soldering profile\. The peak temperature should be 245°C\. The recommended reflow temperature profile is shown in the figure below\.

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Note: The recommended reflow profile above is based on SAC305 solder paste\. For other solder paste alloys, please configure the reflow oven temperature profile according to the recommendations provided in the corresponding solder paste datasheet\.

ESD Protection #

During the entire manufacturing process, appropriate Electrostatic Discharge $ESD$ protection measures must be implemented for the modules\.

Quality Control Recommendations #

To ensure a high production yield, it is recommended to use SPI and AOI inspection equipment to monitor solder paste printing quality and component placement quality\.