Bluetooth 5.x Modules: Technical Sourcing Reference
Sourcing reference for Bluetooth 5.x modules from China. Covers Nordic nRF52840 vs nRF52832 vs EFR32BG22, certified Chinese suppliers, BLE version differences, and FCC/CE grant verification.
Bluetooth 5.x modules are a mature and well-documented sourcing category, but the FCC/CE pre-certification situation is more nuanced than ESP32. Many Chinese suppliers claim certification on modules that carry valid FCC IDs belonging to the chipset reference design, not the specific module you are buying. For wearables and medical-adjacent devices, this distinction is critical.
Overview
Bluetooth Low Energy (BLE) modules integrate a radio SoC, crystal, passive components, and often a PCB trace or ceramic antenna into a castellation-edge package. The dominant chipset vendors are Nordic Semiconductor (Norway), Silicon Labs (US), Qualcomm (US via Airoha/CSR acquisition), and a growing set of Chinese domestic vendors.
BLE 5.x improvements over BLE 4.x are not marketing — Coded PHY (LE Coded) at 125 kbps or 500 kbps doubles effective range on the same power budget. LE Audio (BLE 5.2+) enables LC3 codec audio and multi-stream audio for TWS earbuds. Channel Sounding (BLE 5.4/6.0) enables sub-meter ranging. Choose your BLE version requirement before selecting a chipset family.
Key Specifications
| Parameter | Typical Range | Notes |
|---|---|---|
| Frequency | 2.4 GHz ISM (2402–2480 MHz) | 40 channels, 2 MHz spacing |
| TX power | −20 to +8 dBm (standard) / up to +20 dBm (with PA) | nRF52840 ships up to +8 dBm; PA variants add external amp |
| Receive sensitivity | −95 to −104 dBm at 1 Mbps | −103 dBm typical for nRF52840 |
| Range (indoor) | 10–40 m (1 Mbps PHY) / 100–200 m (Coded PHY, 125 kbps) | Heavily environment-dependent |
| Flash (on-chip) | 256 KB – 1 MB | Nordic: 256 KB (nRF52832) to 1 MB (nRF52840) |
| RAM (on-chip) | 32–256 KB | SoftDevice stack consumes 32–64 KB |
| Current (RX) | 4–7 mA | Key parameter for wearable battery life |
| Current (TX, 0 dBm) | 5–8 mA | Varies by SoC |
| Sleep current | 0.4–2.5 µA | With RAM retention; critical for coin-cell designs |
Main Variants
Nordic Semiconductor nRF52 Series
| SoC | Flash/RAM | BLE Version | Key Features | Module Example |
|---|---|---|---|---|
| nRF52832 | 512 KB / 64 KB | BLE 5.0 | SPI/I2C/UART/PWM, NFC, 32 GPIO | Raytac MDBT42Q |
| nRF52833 | 512 KB / 128 KB | BLE 5.1 | Direction finding (AoA/AoD), USB CDC | Fanstel BT833 |
| nRF52840 | 1 MB / 256 KB | BLE 5.3 | USB 2.0 native, 802.15.4 (Zigbee/Thread), crypto accelerator | Raytac MDBT50Q, u-blox NINA-B4 |
| nRF5340 | 1 MB + 256 KB / 512 KB + 64 KB | BLE 5.4 | Dual-core (app + network), LE Audio (LC3) | u-blox NORA-W10 |
The nRF52840 is the current recommended choice for new designs requiring maximum flexibility: it supports BLE, Thread, Zigbee, and USB in a single SoC. The nRF52832 remains appropriate for cost-sensitive designs where 802.15.4 and USB are not required.
Silicon Labs EFR32BG Series
| SoC | Key Feature | Use Case |
|---|---|---|
| EFR32BG22 | Ultra-low power, 38.4 MHz CPU | Coin-cell beacons, asset tags |
| EFR32BG24 | Matter + BLE 5.3, Security Vault | Smart home devices requiring Matter |
| EFR32MG24 | Multi-protocol: BLE + Zigbee + Thread | Matter bridge devices |
Silicon Labs dominates the Matter-over-Thread space for smart home devices. If your product needs to support Matter, the EFR32MG24 or EFR32BG24 is worth evaluating against nRF5340.
Dialog (Renesas) DA14531
Ultra-compact SoC designed specifically for single-button battery operation. Flash: 1 MB OTP (one-time programmable). Current in advertising mode: 3.3 µA. Used in disposable medical sensors and hearing aids. Limited GPIO count (11 usable). Module options: MikroE SmartBLE Click, custom designs from Shenzhen ODMs.
Certified Chinese Module Suppliers
| Supplier | Module | Chipset | FCC/CE Status | Notes |
|---|---|---|---|---|
| Raytac (瑞泰科技, Taiwan-designed, China-manufactured) | MDBT42Q, MDBT50Q, MDBT50Q-RX | nRF52832, nRF52840 | Valid FCC + CE grants | Most commonly recommended for production; good English docs |
| EBYTE | E104-BT5040U, E73-2G4M08S1E | nRF52840, nRF52832 | CE; FCC varies by model | Verify FCC grant per exact SKU on fcc.gov |
| u-blox | NINA-B4 (nRF52840), ANNA-B112 | Nordic | FCC + CE + TELEC | Swiss company, assembled in China; premium pricing, excellent documentation |
| Laird Connectivity | DVK-BL5340, BL5340 | nRF5340 | FCC + CE | Enterprise-grade, strong US channel; higher price |
| HolyIOT | HY-BLE01, nRF52840 modules | nRF52840 | CE; FCC claims require per-SKU verification | Budget pricing; inspect FCC grants carefully |
Sourcing from China: What to Look For
- Verify the FCC grant is for the specific module model, not just the chipset. Nordic Semiconductor’s FCC grants cover their reference module. A Chinese manufacturer using the same nRF52840 chip in a different PCB layout needs their own FCC grant. Search fcc.gov by FCC ID and confirm the listed grantee and module model match your purchase order.
- FCC ID printed on module ≠ FCC grant for that module. Some Chinese suppliers print the FCC ID from Nordic’s reference design on their own modules. This is fraudulent and is a customs liability risk. Request the DoC (Declaration of Conformity) document and check the grantee name matches your supplier.
- For wearables and medical-adjacent products, budget $8,000–15,000 for per-module certification if pre-certified modules don’t fit your BOM. It is almost always cheaper to design around a Raytac MDBT50Q (which has valid grants) than to certify your own module layout.
- Check RF performance in the actual enclosure, not open-air. Metal enclosures, Li-Po batteries adjacent to the antenna, and hand-holding effects all detune PCB trace antennas significantly. Raytac and u-blox provide antenna placement guidelines — follow them.
- Request production batch traceability. Raytac modules ship with QR codes linking to production batch test data. This is a quality indicator; Chinese white-label modules that cannot provide equivalent documentation should be treated with caution.
Common Issues
FCC ID misrepresentation on Chinese modules: The most legally consequential issue in this category. Customs authorities have seized shipments of BLE modules bearing FCC IDs that do not match FCC database records. If the importer cannot produce a valid grant matching the physical module, the shipment is non-compliant regardless of what the supplier claims.
SoftDevice (Nordic BLE stack) version incompatibility: Nordic SoCs run a proprietary BLE protocol stack (SoftDevice) that must be flashed separately from the application firmware. Modules sometimes ship with older SoftDevice versions (S132 v6 vs v7) that are incompatible with newer Zephyr RTOS or nRF Connect SDK versions. Confirm SoftDevice version in the module datasheet and ensure your firmware development chain targets that version.
Antenna detuning due to hand effect in wearables: BLE 5.x at 2.4 GHz is significantly attenuated by human tissue. Smartwatch designs that place the BLE antenna over the wrist achieve 6–10 dB worse range than open-air specs suggest. This affects OTA update reliability and data sync distance. Test in-body position during design validation.
Certifications Required
| Market | Certification | Cost Estimate | Timeline |
|---|---|---|---|
| US | FCC Part 15C (BLE) | $5,000–12,000 | 8–14 weeks |
| EU | CE (RED 2014/53/EU), EN 300 328 | €4,000–10,000 | 6–10 weeks |
| Canada | IC RSS-247 | Bundled with FCC | +2–4 weeks |
| Japan | TELEC | ¥600,000–1,500,000 | 8–12 weeks |
| South Korea | KC (KCC) | $3,000–8,000 | 6–10 weeks |
| Australia | RCM | AUD 2,500–6,000 | 6–8 weeks |
Pre-certified modules (Raytac, u-blox) reduce end-product certification scope significantly: you still need to certify the complete product, but the radio module portion is covered by the existing grant. Our inspection process verifies FCC grant documentation for every production batch of IoT modules before shipment.