MAX98357 I2S 3W Class-D Audio Amplifier Module

MAX98357 I2S 3W Class-D Audio Amplifier Module Overview

The MAX98357 I2S 3W Class-D Audio Amplifier Module is a compact, high-efficiency digital audio amplifier based on the MAX98357A IC. It accepts I2S digital audio directly and drives a speaker with up to 3W of output power into a 4 ohm load. This module eliminates the need for a separate DAC and is ideal for portable audio devices, IoT projects, and DIY speakers.

Product Photo

Key Features

• MAX98357A I2S Class-D amplifier IC for direct digital audio input
• Up to 3W output power at 4Ω speakers
• I2S input interface (no external DAC required)
• Selectable gain settings: 3dB, 6dB, 9dB, 12dB, 15dB, 18dB
• High efficiency, low distortion, and low noise audio
• Integrated thermal and short-circuit protection for reliability
• Operates from 2.5V to 5.5V for wide compatibility
• Compact PCB design for easy integration into projects

Technical Specifications

• Amplifier IC: MAX98357A
• Input: I2S digital audio (LRCLK/WS, BCLK, DIN/SD)
• Output power: Up to 3W into 4Ω
• Supply voltage: 2.5V to 5.5V
• Gain options: 3dB, 6dB, 9dB, 12dB, 15dB, 18dB
• Protection: Thermal shutdown and short-circuit protection
• Typical use: Single-channel (mono) speaker output

Compatibility and Integration

This module works with microcontrollers and single-board computers that support I2S audio, including ESP32, Raspberry Pi, and Arduino boards with I2S capability. Because the module accepts I2S directly, it removes the need for a separate DAC and simplifies audio pipeline integration.

Basic Wiring Tips

• Connect the board VCC to a stable 2.5V to 5.5V supply and GND to ground.
• Connect I2S signals from the host: LRCLK (WS), BCLK (SCK), and SD (DIN) to the matching pins on the module. Check your board silkscreen for labels.
• Connect a 4Ω speaker to the speaker output terminals provided on the module. Observe polarity.
• Place decoupling capacitors on the supply near the module if your power rail is noisy or the speaker draws bursts of current.
• Refer to your microcontroller documentation for I2S configuration (sample rate, bit depth, and channel format).

Gain Selection and Audio Tuning

The module includes selectable gain steps for system-level volume control. Available gain options are 3dB, 6dB, 9dB, 12dB, 15dB, and 18dB. Choose a gain that matches your speaker sensitivity and desired maximum volume. For cleaner audio, start at a lower gain and increase as needed.

Applications

• DIY portable speakers and Bluetooth speaker projects
• Voice assistants, smart home audio devices, and IoT audio outputs
• Raspberry Pi and ESP32 audio streaming projects
• Educational electronics and hobbyist audio experiments

Practical Tips and Recommendations

• Use a 4Ω speaker for best power delivery; higher impedances will reduce maximum output power.
• Keep speaker wires short to avoid EMI and potential oscillation with the Class-D amplifier.
• If using with battery-powered devices, monitor supply voltage under load; Class-D amplifiers are efficient but transient speaker demands can dip the rail.
• Always follow the module silkscreen and manufacturer datasheet for pinouts and detailed electrical limits.

What You Get

• 1 x MAX98357 I2S 3W Class-D Audio Amplifier Module
• Documentation and example wiring guidelines (online)

Note: Images are for illustration purposes only.