MAX98357A I2S Class-D Mono Audio Amplifier Module

MAX98357A digital audio amplifier for embedded projects

This compact module uses the MAX98357A I2S-input Class-D amplifier to drive a suitable mono speaker from a digital audio source. It can be considered for embedded sound playback, project alerts and small speaker systems with a compatible host controller.

The existing module listing specifies a 3.3–5V supply range, suitable 4Ω or 8Ω speakers and up to 3W output. Actual available output depends on supply voltage, load, distortion limits and the board’s operating conditions; 3W is not guaranteed at every supply and load.

Audio and power connections

• Digital interface: I2S.
• Amplifier type: Class D, mono speaker output.
• Host signals: BCLK, LRCLK/word select and DIN.
• Module supply: listed 3.3–5V DC.
• Speaker: suitable 4Ω or 8Ω load with an appropriate power rating.

Match the host, speaker and wiring

Confirm I2S transmit support and driver configuration on your exact ESP32, Raspberry Pi or other controller. Do not assume that every Arduino board supplies I2S audio or that merely connecting three signal wires provides playable sound. The host must generate compatible clocks and audio data.

Follow the actual module’s power and speaker-terminal markings. Both speaker output terminals are driven in the normal bridged Class-D arrangement; do not treat a speaker terminal as a ground connection or connect it to a grounded audio input. Power down before changing wiring.

This is a speaker amplifier, not a direct analog AUX, headphone, USB or Bluetooth input device. Separate gain or channel-selection options depend on the supplied board’s exposed pins and configuration.

For sound capture, the separate INMP441 I2S microphone module provides a different function. Combining the modules requires compatible host software and interface configuration.

Frequently asked questions

Does it provide stereo speaker outputs?

One module provides mono output. A stereo project needs an appropriate multi-channel arrangement.

Can I feed it an analog headphone signal?

Not directly. The input is digital I2S audio.

Is the speaker included?

A speaker or host controller is not established as part of the package.