WT2605A4-16S-R Voice Recorder Chip
Compact SOP16 Voice Chip with MP3 Playback, Recording & BLE 5.4 Transparent Transmission
The WT2605A4-16S-R is a high‑performance voice recorder chip in a compact SOP16 package, powered by a 32‑bit processor running at up to 192MHz. It supports MP3/WAV decoding and high‑quality recording with storage on SPI‑Flash, TF card, or USB drive. Integrated BLE 5.4 transparent transmission enables wireless data transfer, while the UART interface (115200 baud) provides simple command control for playback, volume, loop, random, and recording functions.
- 32‑bit DSP – 192MHz for smooth audio processing
- MP3/WAV playback – 8–44.1kHz, 8–320kbps
- Recording – up to 4090s @ 16kbps (64Mbit Flash)
- BLE 5.4 – transparent transmission
- Multi‑storage – SPI‑Flash, TF, USB
Recording Duration Reference
| Bitrate | 16Mbit Flash | 32Mbit Flash | 64Mbit Flash |
|---|---|---|---|
| 16 kbps | ~1020s | ~2040s | ~4090s |
| 32 kbps | ~510s | ~1020s | ~2040s |
| 64 kbps | ~250s | ~510s | ~1020s |
Formula: Recording time (s) = [Flash capacity (Mbit) × 1024] ÷ bitrate (kbps). External Flash up to 256Mbit.
WT2605A4-16S-R Key Features
Technical Specifications
| Parameter | Value |
|---|---|
| Package | SOP16 |
| Processor | 32‑bit, up to 192MHz |
| Operating Voltage | 2.6V – 5.2V |
| Audio Formats | MP3, WAV (8–44.1kHz, 8–320kbps) |
| Recording | Supported (bitrate selectable) |
| Storage Media | SPI‑Flash (256Mbit), TF card (128GB), USB (128GB) |
| Bluetooth | BLE 5.4 transparent transmission |
| Control Interface | UART (115200 baud) |
| Volume Levels | 32 levels |
| Audio Output | 16‑bit DAC (1Vrms, 95dB SNR) |
| DAC THD+N | ‑75dB @ 1kHz |
| ADC SNR | 90dB |
| Power‑up Init Time | 930ms – 1.5s |
| Operating Temp | ‑40°C ~ +85°C |
Pin Functions (SOP16)
| Pin | Name | Function |
|---|---|---|
| 1 | RX | UART receive |
| 2 | TX | UART transmit |
| 3 | DAT/DM | USB D− / Programming |
| 4 | CLK/DP | USB D+ / Programming |
| 5 | BUSY | Busy output |
| 6 | P03 | GPIO |
| 7 | MICLDO | MIC power supply |
| 8 | MIC+ | MIC input (+) |
| 9 | P00 | GPIO |
| 10 | DACVSS | DAC ground |
| 11 | VCM | 1µF cap to ground |
| 12 | DAC | DAC output |
| 13 | SPI_SO/SDCLK | Flash data out / SD clock |
| 14 | SPI_CLK/SDCMD | Flash clock / SD select |
| 15 | SPI_CS/SDDAT | Flash select / SD data |
| 16 | SPI_SI | Flash data in |
| 17 | VCC | Power (2.6–5.2V) |
| 18 | VOUT | 1µF cap to ground |
| 19 | ADKEY | Analog key input |
| 20 | GND | Ground |
| 21 | NC | Not connected |
| 22 | ANT | Bluetooth antenna |
| 23 | OSCI | Crystal oscillator input |
| 24 | OSCO | Crystal oscillator output |
WT2605A4-16S-R Applications
Frequently Asked Questions
What audio formats does WT2605A4-16S-R support?
It supports MP3 and WAV formats with sampling rates from 8kHz to 44.1kHz and bitrates from 8kbps to 320kbps.
Does it support recording?
Yes, it supports high-quality recording. Recording duration depends on Flash size and bitrate. With 64Mbit Flash at 16kbps, it can record up to 4090 seconds.
What storage media are supported?
WT2605A4-16S-R supports SPI-Flash (up to 256Mbit), TF card (up to 128GB), and USB drive (up to 128GB). Note: Flash and TF card cannot be mounted simultaneously.
Does WT2605A4-16S-R have Bluetooth?
Yes. WT2605A4-16S-R features BLE 5.4 transparent transmission. A 24MHz crystal is required for Bluetooth functionality.
How is the chip controlled?
It uses a standard UART interface with default baud rate 115200. Commands follow a 7E … EF protocol for playback, volume, loop, random, and recording control.
What is the operating voltage?
The chip operates from 2.6V to 5.2V, making it compatible with both 3.3V and 5V systems.
What is the package of WT2605A4-16S-R?
WT2605A4-16S-R comes in a 16-pin SOP (SOP16) package.
What is the initialization time?
Due to USB mass storage emulation, initialization takes about 930ms to 1.5s. Wait at least 1.5s before sending commands.
Can I copy audio files via USB?
Yes. Connect to a PC via USB, copy audio files to the drive, then disconnect USB before sending serial commands.
What are the typical applications?
Bluetooth speakers, voice prompt devices, smart home controllers, recording equipment, industrial alarms, toys, and any application requiring MP3 playback, recording, or BLE data transmission.
Important: A 24MHz crystal is required for Bluetooth. If Bluetooth is not used, the crystal and antenna can be omitted. Flash and TF card cannot be mounted simultaneously. For external Flash, Waytronic‑branded Flash is recommended. R1 resistor: 0Ω for 3.3V VBAT; 33Ω for 5V to suppress high‑voltage pulses.
