MAX98357 I2S Class D Amplifier Breakout Board 3W Filterless

The MAX98357 I2S Class D Audio Amplifier Breakout Module is a compact, filterless mono DAC + amplifier board that takes standard I2S digital audio input, decodes it into an analog signal, and drives a speaker directly — all in one tiny package. Whether you're building a Raspberry Pi music player, an Arduino Zero sound project, or an ESP32 IoT device, this board delivers clear, amplified audio with minimal components and wiring.

Key Features

• 3.2W Output Power — Drives a 4Ω speaker at 3.2W (10% THD) or an 8Ω speaker at 1.8W with a 5V supply
• Class D Efficiency — Highly efficient design ideal for portable and battery-powered projects (2.7V–5.5V operating range)
• No MCLK Required — Simplified wiring; works directly from I2S data, bit clock, and LR clock pins
• Wide Sampling Rate — Supports I2S audio from 8kHz up to 96kHz
• Filterless Output — PWM output (~300kHz) is averaged by the speaker coil, so no external LC filter is needed
• Adjustable Gain — Five selectable gain settings: 3dB, 6dB, 9dB (default), 12dB, or 15dB via pull-up/pull-down resistors
• Stereo-to-Mono Mixing — Default mode mixes (L+R)/2 to mono output; configurable to left or right channel only
• Built-in Thermal & Overcurrent Protection — Automatic shutdown protection keeps the board safe during demanding use
• Excellent Click & Pop Suppression — Clean audio transitions on power-up and power-down
• 3.3V or 5V Logic Compatible — Works seamlessly with both 3.3V and 5V microcontrollers
• Assembled & Tested Board — Ships ready to use; optional header pins and terminal blocks may require soldering

Technical Specifications

• Chip: MAX98357A
• Output Power: 3.2W @ 4Ω / 1.8W @ 8Ω (5V, 10% THD)
• Supply Voltage: 2.7V – 5.5V DC
• PSRR: 77dB typical @ 1kHz
• I2S Sampling Rate: 8kHz – 96kHz
• Gain Options: 3 / 6 / 9 / 12 / 15 dB
• Output Type: Bridged (BTL) — do NOT connect to another amplifier input
• Package Type: SMD breakout board
• Compatible With: Raspberry Pi 4/5, Arduino Zero, ESP32, and any microcontroller or microcomputer with I2S audio output

How It Works

I2S (Inter-IC Sound) is the standard digital audio protocol used to pass audio data between chips on a circuit board. The MAX98357 accepts I2S data (BCLK, LRCLK, DIN) and performs both DAC conversion and amplification in a single step — eliminating the need for a separate DAC chip. The bridged output delivers a pulse-width-modulated signal that your speaker coil naturally averages into clean audio. No bulky filter components required.

What's in the Box

• 1 × MAX98357 I2S Class D Amplifier Breakout Board (assembled and tested)
• Optional small header and 3.5mm terminal block included (soldering required if headers/strips are needed)

Perfect For

• Raspberry Pi audio projects (Pi 4, Pi 5, Pi Zero)
• Arduino Zero, Arduino MKR series builds
• ESP32 and ESP8266 audio projects
• DIY Bluetooth or Wi-Fi speakers
• Portable battery-powered audio systems

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Frequently Asked Questions

Q: What microcontrollers are compatible with the MAX98357 I2S Class D Audio Amplifier Breakout Module?

A: This board is compatible with any microcontroller or microcomputer that supports I2S audio output, including Raspberry Pi 4, Raspberry Pi 5, Raspberry Pi Zero, Arduino Zero, Arduino MKR series, ESP32, and ESP8266. It accepts both 3.3V and 5V logic levels, making it extremely versatile for maker and IoT projects.

Q: Do I need an external filter or DAC with the MAX98357 breakout board?

A: No. The MAX98357 combines a DAC and a Class D amplifier in a single chip, so no external DAC or LC filter is required. The ~300kHz PWM output is filtered naturally by the speaker coil, keeping your build compact and simple. The board requires no MCLK signal either, further simplifying connections.

Q: How do I adjust the gain on the MAX98357 amplifier board?

A: The gain is set via the GAIN pin. By default (pin left floating), the amplifier operates at 9dB gain. You can change the gain to 3dB, 6dB, 12dB, or 15dB by connecting the GAIN pin to ground or VDD through the appropriate pull-down or pull-up resistor, as specified in the MAX98357 datasheet.

Q: Can I connect the output of the MAX98357 to another amplifier?

A: No — the output is bridged (BTL) and outputs a high-frequency PWM signal. It must be connected directly to a speaker (4Ω or 8Ω recommended). Connecting it to the input of another amplifier will damage the downstream device. Use it to drive a speaker directly only.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.