MAX98357 I2S 3W CLASS D AMPLIFIER INTERFACE AUDIO DECODER MODULE

Description

MAX98357 I2S 3W Class D Amplifier Interface Audio Decoder Module is a compact, filterless audio module that combines an I2S DAC and a high-efficiency Class D amplifier, allowing direct connection from digital controllers (like Raspberry Pi or ESP32) to speakers for up to 3.2 W output.

Key Specifications:

• Output Power: Up to 3.2W @ 4Ω, 5V supply (1.8W @ 8Ω)

• Operating Voltage: 2.7V to 5.5V (works with both 3.3V and 5V I2S levels)

• Supported Inputs: I2S digital audio (Left/Right-Justified)

• Selectable Gain: 3dB, 6dB, 9dB, 12dB, 15dB controlled by gain pin/input

• Efficiency: Up to 92% (Class D)

• THD+N: <0.01% (high fidelity, low noise)

• Speaker Load: 3Ω to 8Ω supported

• No MCLK Required: Simplifies microcontroller interfacing

• Protections: Short-circuit and thermal protection

• Size: ~14–21 mm x 14–20 mm x 3 mm, lightweight

• Output Type: Mono (default mixes L+R, resistor configuration sets single channel)

• Application Examples: Portable speakers, IoT voice output, direct interface with Raspberry Pi/ESP32/Arduino

Pinout and Connections:

• VIN/GND: Power input (2.7–5.5V)

• LRCLK (WS): Frame clock

• BCLK: Bit clock

• DIN (SD): Data in (I2S)

• GAIN: Sets amplification

• SD: Shutdown/channel selection

• LOUT/ROUT: Connect to speaker

• GND: Ground

By default, the module mixes Left + Right channels, but configuration is possible for individual channel output using resistor settings.

Notable Features:

• Filter less output—no need for bulky external LC filter due to spread-spectrum modulation scheme

• Robust EMI and RF noise immunity

• No need for Master Clock (MCLK), simplifying hardware design

• Wide sample-rate support: 8kHz–96kHz

• Delivered fully assembled and tested (for most module variants)

• Ideal for battery-powered and portable audio applications due to minimal quiescent current and high efficiency

• Plug-and-play with development boards (Raspberry Pi, ESP32, Arduino)