MAX98357 I2S 3W Class D Amplifier Module – Filterless Audio Decoder and Amplifier Interface

All Technical Details

• Pin Definition:

  • Vin / GND: Power Input (3.3V to 5V).

  • LRC (Left/Right Clock): Word Select clock for I2S.

  • BCLK (Bit Clock): Serial Data clock for I2S.

  • DIN (Data In): Digital audio data signal.

  • GAIN: Adjustable gain (3dB, 6dB, 9dB, 12dB, or 15dB) via resistor/connection.

  • SD (Shutdown): Used for power-down or channel selection.

• Protection Logic: Integrated thermal and short-circuit protection to prevent damage during accidental overloads.

• Applications: Smart speakers, internet radio, walkie-talkies, and robotic voice systems.

Prototyping & Engineering Tips (Robogears Exclusive)

• Powering for Volume: To achieve the full 3.2W output, power the module with a stable 5V DC supply. Powering with 3.3V will result in lower maximum volume.

• ESP32 Setup: When using with an ESP32, utilize the ESP32-A2DP or I2S libraries. Ensure your BCLK, LRC, and DIN pins match the software definition, as these can be remapped to almost any GPIO on the ESP32.

• Mono vs Stereo: If you want a stereo setup, you will need two MAX98357 modules. Connect them to the same I2S bus but pull the "SD" pin of one module to VCC through a resistor for the Left channel and ground it through a resistor for the Right channel.

• Speaker Matching: For best performance, use a 4-ohm or 8-ohm speaker. Avoid using standard "PC" speakers that already have an internal amplifier; this module is designed to drive "raw" speaker drivers directly.

Package Includes

• 1 x MAX98357 I2S 3W Class D Amplifier Module

• 1 x 7-pin Male Header

• 1 x 2-pin Screw Terminal Block (for speaker connection)

Image Disclaimer

Product images are shown for illustrative purposes only. The color of the PCB (typically Purple or Blue) or the style of the screw terminal may vary between batches, but the MAX98357 digital-to-analog amplification performance remains as described.