WT2605-24SS Bluetooth Audio Chip
Dual‑Mode Bluetooth 5.0 with 120MHz DSP, 16‑bit DAC/ADC & UART Control
The WT2605-24SS is a high‑performance dual‑mode Bluetooth 5.0 audio chip designed for wireless audio applications. Powered by a 32‑bit DSP up to 120MHz, it features a 16‑bit DAC with 96dB SNR and a 16‑bit ADC with 90dB SNR for pristine audio quality. With UART control (115200 baud), support for SPI‑Flash, TF card, and USB drive storage, and a compact SSOP24 package, it is ideal for Bluetooth speakers, headphones, and smart home audio devices.
- 32‑bit DSP – 120MHz for smooth audio processing
- Dual‑mode BT 5.0 – audio + BLE
- 16‑bit DAC – 96dB SNR for superior output
- 16‑bit ADC – 90dB SNR for clear input
- UART control – simple command set
Key Features
Audio & Bluetooth Specifications
| Parameter | Value |
|---|---|
| DAC Resolution | 16‑bit |
| DAC SNR | 96 dB (A‑Weighted) |
| DAC THD+N | ‑86 dB |
| DAC Max Output | 2.6 Vpp (32Ω loading) |
| ADC Resolution | 16‑bit |
| ADC SNR | 90 dB (A‑Weighted) |
| ADC THD+N | ‑87 dB |
| Sample Rates | 8, 11.025, 12, 16, 22.05, 32, 44.1, 48 kHz |
| Bluetooth Version | 5.0 (BR/EDR + BLE) |
| Bluetooth Profiles | A2DP, AVRCP, HFP, SPP, GATT |
| RF Output Power | +2 dBm (typical) |
| Audio Formats | MP3 (≤48kHz, ≤320kbps), WAV (≤44.1kHz, ≤384kbps) |
UART Command Highlights
| Command | Function | Description |
|---|---|---|
| A0 | Index Flash Playback | Play by index in SPI‑Flash |
| A2/A3 | TF Card Playback | By index or filename |
| A6/A7 | USB Playback | By index or filename |
| AA | Pause / Resume | Toggle pause |
| AB | Stop | Stop playback |
| AC/AD | Next / Previous | Track navigation |
| AE | Volume Control | 0–31 (default 26) |
| AF | Playback Mode | Normal / Single loop / All loop / Folder loop / Random |
| B1 | Insert Playback | Insert a track during playback |
| B2 | EQ Format | Normal / Pop / Rock / Jazz / Classic / Bass |
| B3/B4 | Get Duration | Total / current playback time (TF/USB) |
| BB | Switch Mode | Bluetooth ↔ MP3 (local playback) |
| BC/BD | Call Control | Answer / end call |
| C0–C2 | Queries | Version, volume, status |
| C5–C9 | File Queries | File count on TF/USB, current track |
| CB | Song Name | Current song name (MP3 mode) |
| D1–D3 | Bluetooth Name | Change/query name and MAC |
| E2–E5 | Delete Files | Delete by index or filename |
| E7 | Copy from USB | Copy audio from USB to Flash |
| FF 05 | Extended Commands | BLE data, song info, phonebook, etc. |
Protocol format: 7E + Length + Command + Parameters + Checksum + EF. Return codes: 0x00 = OK, 0xFE = format error, 0xFF = execution error.
Technical Specifications
| Parameter | Value / Condition |
|---|---|
| Package | SSOP24 |
| Processor | 32‑bit DSP, up to 120MHz |
| Operating Voltage | 3.0V – 5.0V |
| DAC SNR | 96 dB (A‑Weighted) |
| ADC SNR | 90 dB (A‑Weighted) |
| Audio Formats | MP3 (≤48kHz, ≤320kbps), WAV (≤44.1kHz, ≤384kbps) |
| External Storage | SPI‑Flash (128Mbit), TF (32GB), USB (32GB) |
| Control Interface | UART (115200 baud) |
| Volume Levels | 31 (0–31, default 26) |
| Bluetooth | 5.0, dual‑mode (BR/EDR + BLE) |
| Bluetooth Name | BT_WT2605 (audio), LE_WT2605 (BLE) |
| Crystal | 26MHz, 7.5/9pF, ±10PPM |
| Operating Temperature | ‑40°C ~ +85°C |
| IO Drive Capability | 8 mA |
Pin Functions (SSOP24)
| Pin | Name | Function |
|---|---|---|
| 5 | TXD | UART transmit |
| 6 | RXD | UART receive |
| 7 | SPI_CS / IR | SPI chip select / IR input |
| 9 | VDDIO | 3.3V LDO output |
| 10 | VBAT | Power input (3.0–5.0V) |
| 13 | PWRKEY | Button input (customizable) |
| 14 | BLUE_ANT | Bluetooth antenna |
| 15 | OSCI | 26MHz crystal input |
| 16 | OSCO | 26MHz crystal output |
| 17 | USBDM | USB D− |
| 18 | USBDP | USB D+ |
| 19 | SDDAT / SPIDO | SD data / SPI data out |
| 20 | SDCLK / SPICLK | SD clock / SPI clock |
| 21 | SDCMD / SPIDI | SD command / SPI data in |
| 22 | MIC+ / AUX_L | MIC positive input / AUX left |
| 23 | DACR | DAC right channel output |
| 24 | DACL | DAC left channel output |
SPI and SD card share the same pins and cannot be used simultaneously. The PWRKEY function requires custom firmware – contact Waytronic for details.
Application Scenarios
Why Choose WT2605-24SS
Frequently Asked Questions
What is the WT2605-24SS?
WT2605-24SS is a dual-mode Bluetooth 5.0 audio chip with a 32-bit DSP up to 120MHz, 16-bit DAC (96dB SNR) and ADC (90dB SNR), UART control, and support for SPI-Flash, TF card, and USB storage in a SSOP24 package.
What Bluetooth profiles are supported?
WT2605-24SS supports A2DP, AVRCP, HFP, and BLE (GATT) profiles for music streaming, remote control, hands-free calling, and data transmission.
What is the Bluetooth name?
The default audio Bluetooth name is ‘BT_WT2605’ and the BLE name is ‘LE_WT2605’. Both can be changed via serial commands.
What storage media are supported?
WT2605-24SS supports SPI-Flash up to 128Mbit, TF card up to 32GB, and USB drive up to 32GB. The chip can switch between Bluetooth mode and MP3 mode for local playback.
What is the audio quality?
WT2605-24SS features a 16-bit DAC with 96dB SNR and a 16-bit ADC with 90dB SNR, delivering high-quality audio input and output.
What control interface does it use?
WT2605-24SS uses a standard UART interface with default baud rate 115200. Commands follow a 7E … EF protocol for playback, volume, EQ, and BLE control.
Does it support phone calls?
Yes. It supports HFP for hands-free calling, with commands to answer, end, and redial calls. Incoming call number and phonebook can also be queried (custom firmware required).
What is the operating voltage range?
The chip operates from 3.0V to 5.0V, compatible with both 3.3V and 5V systems.
What is the recommended Bluetooth range?
The recommended range is within 10 meters for optimal performance. Proper PCB layout and antenna design are required.
What are the typical applications?
Bluetooth speakers, stereo headsets, car audio systems, smart home devices, voice recorders, and any application requiring wireless audio streaming with local storage playback.
Important: A 26MHz crystal (7.5/9pF, ±10PPM) is required for Bluetooth operation. SPI‑Flash and SD card share the same pins – they cannot be used simultaneously. The chip defaults to Bluetooth mode on power‑up; use the BB command to switch to MP3 mode. For external Flash, Waytronic‑branded Flash is recommended. The PWRKEY function and phonebook features require custom firmware – contact Waytronic for details. The USB interface can function as a sound card, but Bluetooth audio is disabled in that mode.
