The WTV020SD is a small, simple IC for embedding audio-playback into your next project. This audio module allows you to access the functionality of the WTV020SD to give a voice to your next project.

The module includes a battery connector and a micro-SD card slot. Simply load your audio files onto a micro-SD card and plug it in, power up the module and trigger the playback. Playback can be triggered in either key or serial mode:

The key-mode provides a stand alone operation where a host microcontroller is not required. With only 3 push buttons, a 3V battery and a speaker, an extremely compact and low component count MP3-Player like system can be implemented.

The serial-mode provides a simple, 2-wire interface to any micro-controller via its DATA and CLK lines. Audio operations such as PLAY, PAUSE, STOP and VOLUME control functions are all available to the host micro via simple serial commands.

The audio compression used in this module is a little strange (4-bit ADPCM @ 6-32kHz) so you’ll need to use a software in order to convert your .WAV files into the 4-bit ADPCM format required.

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  • On-board micro-SD memory card adaptor for storing of audio, voice and music files (up to 512 files).
  • Supports 64Mb to 2Gig micro-SD memory cards (FAT format).
  • Low-cost module for all embedded Audio-Sound applications.
  • Supports 4-bit ADPCM (.ad4) file formats with sampling rates from 6Khz to 36Khz.
  • Two operation modes:
    • Serial Mode: Supports a 2-Wire (Data, Clock) interface to any micro-controller.
    • Key Mode: Supports a simple stand alone operation without a host micro.
  • Differential 2 line PWM output for direct speaker connection (8 Ohm/0.5W).
  • Dedicated 16-bit DAC/PWM audio output to use with an external amplifier.
  • Low power

Technical Specifications

  • Low Power Idle current: 8.0uA
  • Operating Voltage: 3.3V  (Through an SMD jumper * Note-1),
    • Min: 2.7V
    • Max: 3.5V
  • Dimensions: 20 mm (L) x 18mm (W) x12mm (H)

[!] Note: An SMD jumper (on top side of the pcb between pins 1 and 16) must be bridged by soldering prior to use this module. The jumper selects operating voltage between 3.3V or 5V. The 5V to 3.3V regulator is not installed on these modules. Therefore the only option you can select is 3.3V. Please see image 2/2



  • Automobile car bug, parking radar, GPS navigation system
  • Intelligent home system, house bug
  • Voice in medical devices
  • Household appliances (induction cooker, rice cooker, micro-wave oven),
  • Game machines and
  • Learning toys: talking book
  • Voice Tools
  • Intelligent traffic facilities: automated toll gate, automated parking lot
  • Communications equipment: Telephone, PABX exchanged
  • Hotel Management: Room and Hotel Manegement
  • Industrial control: Elevator, toys and in other applications

Documents and downloads