The MAX98357 is a digital audio amplifier module combining an I2S interface, digital audio conversion and Class D amplification, allowing an I2S audio source to drive a compatible speaker directly.

The module operates from a single 2.5 to 5.5 V DC supply and can deliver up to 3.2 W into a 4 Ω load at 5 V, according to the specifications published by NAFCOM.

It uses the digital I2S audio protocol and does not require an external MCLK signal, simplifying connection to compatible microcontrollers and microcomputers.

Sample rates from 8 kHz to 96 kHz are supported, with selection of the left, right, or (L/2 + R/2) audio signal for mono playback.

The Class D output provides high efficiency, with the source listing 92% efficiency at an 8 Ω load and 1 W output.

Main features

Type: digital audio amplifier module
IC: MAX98357
Input interface: digital I2S
Amplifier: Class D
Output: mono
Supply voltage: 2.5 to 5.5 V DC
Output power: up to 3.2 W into 4 Ω at 5 V
Quiescent current: 2.4 mA
Listed efficiency: 92% at RL = 8 Ω, POUT = 1 W
RMS output noise: 25 µV at AV = 15 dB
THD+N: 0.015% at 1 kHz
Sample rates: 8 to 96 kHz
External MCLK: not required
Audio selection: left, right or L/2 + R/2
PSRR: 77 dB at 1 kHz
Filterless Class D output: yes
Click-and-pop reduction: yes
Short-circuit protection: yes
Thermal protection: yes
RF/TDMA interference rejection: yes
Main application: I2S digital audio playback and amplification.

Recommended applications

Raspberry Pi I2S audio projects
ESP32 and compatible microcontrollers
Arduino projects with I2S hardware
Voice and audio notification systems
IoT devices
DIY digital radios
Intercom systems
Speech synthesis and playback
Compact speakers for electronic projects
Digital audio prototyping

Important note

This module accepts digital I2S audio only. It does not provide a conventional analogue audio input, so headphone or line-level analogue signals cannot be connected directly.

The amplifier output is BTL (Bridge-Tied Load). The speaker must be connected directly between the two amplifier outputs; neither speaker terminal should be connected to GND.

At 5 V, a typical MAX98357 implementation can provide approximately 3 W into 4 Ω or 1.8 W into 8 Ω, depending on operating conditions and acceptable distortion.

Do not use the Class D speaker output as a line-level output or feed it into another amplifier.

This item corresponds only to the MAX98357 amplifier module. Speaker, Raspberry Pi, ESP32, microcontroller, power supply, cables and other accessories are not included unless expressly stated otherwise