The FEASYCOM FSC-BT646 is a low-power Bluetooth module based on the BLE 4.2 protocol, built around a 32-bit MCU that can serve as either an application processor or a data pump in a fully hosted system. Its stamp hole dimensions (13 × 26.9 × 2.0 mm) and ultra-low power consumption make it ideal for battery-powered and energy-harvesting applications.
The module delivers strong RF performance. Transmit power reaches up to +13dBm (Class 1), with a typical receiver sensitivity of -90dBm, using GFSK modulation in the 2.402 – 2.480 GHz frequency band. Sleep current is exceptionally low — just 503.72 µA in discoverable mode and 586.52 µA in LE connected state — making it suitable for small coin cell batteries and energy-harvesting scenarios.
The FSC-BT646 offers a rich set of peripheral interfaces including UART, I2C, SPI, 12-bit ADC, and PWM. The UART interface supports a wide baud rate range from 1200 to 921600 bps, with a default configuration of 115200, N, 8, 1. The module can be configured with up to 22 GPIOs, supports 5/6/7/8-bit data characters, and includes built-in 33 KΩ pull-up resistor control. The PWM interface provides up to 4× 16-bit PWM generators, capable of outputting 8 PWM signals or 4 pairs of complementary PWM outputs.
The module is configured through AT commands, allowing users to modify device name, baud rate, master/slave mode, transparent transmission mode, and other parameters using simple serial commands. By default, the module operates in slave mode (GATT Server) with transparent mode disabled, service UUID FFF0, write characteristic UUID FFF2, and notify characteristic UUID FFF1. For applications requiring mobile app connectivity, the module also supports BLE password functionality, with readable and writable pairing password and authentication type.
The FSC-BT646 has achieved SRRC, FCC, CE, and BQB certifications, ensuring compliance and interoperability. The module is widely used in automotive electronics, healthcare devices, smart locks, and electronic toys.
Features
-
BLE 4.2 low-power protocol — Supports L2CAP, SM, ATT, GATT, and GAP protocol stacks
-
Integrated 32-bit MCU — Can function as application processor or data pump
-
Stamp hole package — Compact 13 × 26.9 × 2.0 mm form factor for space-constrained designs
-
Wide baud rate range — UART supports 1200 to 921600 bps, default 115200
-
Rich peripheral interfaces — UART, I2C, SPI, 12-bit ADC, PWM, up to 22 GPIOs
-
AT command configuration — Modify name, baud rate, master/slave mode via serial commands
-
Ultra-low power consumption — Sleep current as low as 503.72 µA, suitable for coin cell and energy-harvesting applications
-
Multi-country certifications — SRRC, FCC, CE, and BQB certified for global compliance
Technical Specifications
| # | Parameter | Specification |
|---|---|---|
| 1 | Bluetooth Version | BLE 4.2 |
| 2 | Operating Frequency | 2.402 – 2.480 GHz |
| 3 | Transmit Power | +13 dBm (maximum) |
| 4 | Receiver Sensitivity | -90 dBm (typical) |
| 5 | Operating Voltage | 2.2V – 3.6V |
| 6 | Operating Temperature | -40°C to +85°C |
| 7 | UART Baud Rate | 1200 – 921600 bps (default 115200) |
| 8 | Dimensions | 13 × 26.9 × 2.0 mm |
