Description

MAX98357A I2S 3W Class D Amplifier Module

The MAX98357A I2S 3W Class D Amplifier Module combines an I2S digital audio interface, digital-to-analog conversion, and an efficient mono Class D speaker amplifier on one compact board. It can receive digital audio directly from a compatible microcontroller or single-board computer and drive a speaker without requiring a separate analog DAC.

Assembly notice: This module is supplied unassembled and not soldered. The included 2-pin screw terminal and 7-pin male header are supplied loose and require soldering before use.

[IMAGE SLOT: microohm_913.webp — Front view of the unsoldered MAX98357A module]

Key Features

• Direct digital audio input through the I2S interface.
• Integrated DAC and mono Class D speaker amplifier.
• Up to 3.2W output into a 4Ω speaker with a 5V supply.
• Wide 2.5–5.5VDC operating voltage range.
• Supports audio sample rates from 8kHz to 96kHz.
• Supports 16-bit, 24-bit, and 32-bit digital audio data.
• Selectable 3dB, 6dB, 9dB, 12dB, or 15dB gain.
• Default 9dB gain when the GAIN pin is left unconnected.
• Up to 92% efficiency under the specified operating conditions.
• Compact size for embedded and portable audio projects.

Technical Specifications

Pinout & Pin Functions

[IMAGE SLOT: microohm_910.webp — MAX98357A pinout diagram]

Wiring & Connection

• Connect VIN to a regulated 2.5–5.5VDC power supply.
• Connect GND to the controller ground.
• Connect BCLK, LRC, and DIN to the matching I2S signals.
• Connect the speaker between OUT+ and OUT− only.
• Do not connect either speaker output terminal to GND.
• Solder the supplied screw terminal and pin header before use.

[IMAGE SLOT: microohm_912.webp — Example of the module after soldering]

Dimensions & Construction

The board measures approximately 18 × 19mm. The terminal block and pin header are supplied separately, allowing the required mounting direction to be selected before soldering.

[IMAGE SLOT: microohm_915.webp — MAX98357A board dimensions]

[IMAGE SLOT: microohm_914.webp — Rear view of the MAX98357A module]

Compatibility

The module works with controllers and computers that provide a compatible I2S audio output, including many ESP32 boards and Raspberry Pi models. It does not accept a normal analog AUX audio signal.

It can be paired with this ESP32 development board for digital audio projects. You can also browse additional products in the Audio Amplifier Modules category.

Applications

• ESP32 and Raspberry Pi audio projects.
• Portable mono speaker systems.
• Voice assistants and notification devices.
• Interactive installations with audio feedback.
• Custom digital audio players.
• Educational electronics and embedded prototypes.

Package Contents

• 1 × MAX98357A I2S amplifier module — unsoldered.
• 1 × 2-pin screw terminal — loose and unsoldered.
• 1 × 7-pin male header — loose and unsoldered.

Important Notes

• The terminal and male pin header are not soldered to the module.
• Soldering tools and solder are not included.
• The module provides a mono differential speaker output.
• Never connect OUT+ or OUT− directly to ground.
• Use a stable power supply capable of supplying the speaker current.
• Actual output depends on the supply voltage, speaker impedance, audio signal, and operating conditions.

Attachments & Datasheets

Download the MAX98357A / MAX98357B Datasheet PDF