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MAX98357A I2S Digital Amplifier Module

SKU: DFR0954

This MAX98357A I2S Class D amplifier module works with I2S-enabled MCUs like ESP32 for IoT node audio, smart home voice interaction, and Bluetooth audio player projects. It runs on 3.3V-5V and outputs up to 2.5W into a 4Ω speaker (at 12dB gain). Channel mode (off/left/right/mixed, default mixed) is set via SD port resistance, while output gain (3dB-15dB, 5 steps) is set independently via the GAIN pin. Stamp-hole design supports both PCB/breadboard mounting and PH2.0 or stamp-hole speaker connections.

Front of MAX98357 I2S amp module with pins and microcontroller chip.-DFRobot product sku:DFR0954 image.

Downloadable Resources

  • Docs
  • Tech Specs
  • Projects
    • 1. Example Code for ESP32 Play Music via Bluetooth

    Enable ESP32-E Bluetooth function, create a Bluetooth node named bluetoothAmplifier, and use a phone with Bluetooth function to connect that node to play music. Users can learn how to interface the I2S digital amplifier with an ESP32 microcontroller, configure Bluetooth on the ESP32, and connect a speaker for audio output.
    2. Example Code for ESP32 Play Music from SD Card

    Connect to an SD card module to play music files from an SD card using the I2S amplifier and ESP32. Users can learn how to interface the SD card module with the ESP32, scan for music files on the SD card, and control audio playback using the I2S amplifier.
    API Description

    The article serves as a reference for the I2S Amplifier Library for Arduino, detailing its installation, communication protocol, and key functions such as audio playback, Bluetooth control, and SD card management.

    Specification

    Module Parameter

    Parameter Details
    MCU MAX98357A
    Operating Voltage DC 3.3V~5V
    Output Power 8Ω 1.8W / 4Ω 2.5W (at 12db)
    Output Channel single channel
    Communication Interface I2S interface
    Operating Temperature -40℃ - ＋80℃
    Storage Temperature -40℃ - ＋80℃
    Dimension (Without Packaging) 18mm × 18mm/ 0.059 × 0.059

    Chip Audio-relevant Parameters

    • VDD = 5V, VGND = 0V, GAIN_SLOT = VDD. BCLK = 3.072MHz, LRCLK = 48kHz
    • speaker loads (ZSPK) connected between OUTP and OUTN, ZSPK = J, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.
    Parameter Details
    Sample Rate 8kHz~96kHz
    THD 0.02% (f = 1kHz, POUT = 1W, TA = +25NC, ZSPK = 4I + 33FH, TQFN); 0.013% (f = 1kHz, POUT = 0.5W, TA = +25NC, ZSPK = 8I + 68FH)
    Dynamic Range 105DB (A-weighted, VRMS = 2.54V, 24- or 32-bit data)
    Output Noise 25FVRMS (A-weighted, 24- or 32-bit data (Note 4))
    Efficiency 92% (ZSPK = 8I + 68FH, THD+N = 10%, f = 1kHz, gain = 12dB)
    DAC Gain Error 1%
    Frequency Response ±0.2dB
    Class D Switching Frequency 330kHz
    Spread Spectrum Bandwidth ±12.5kHz

    Gain (relative to reference level of 2.1dBV)

    GAIN_SLOT Configuration Min Typical Max
    GAIN_SLOT = GND through 100kΩ 14.4dB 15dB 15.6dB
    GAIN_SLOT = GND 11.4dB 12dB 12.6dB
    GAIN_SLOT = unconnected 8.4dB 9dB 9.6dB
    GAIN_SLOT = VDD 5.4dB 6dB 6.6dB
    GAIN_SLOT = VDD through 100kΩ 2.4dB 3dB 3.6dB

    Product Dimension

    Dimension

    Pinout

    Board Overview

    Board Overview

    Pin Function Remark
    SPK- Speaker negative 4Ω/8Ω ＜3W
    VCC Power input DC 3.3V-5V
    GND Ground
    NC Not connected pin
    SD Turn off amplifier, adjust sound channel Refer to 4.1.2(SD Mode Description)
    GAIN Adjust amplifier gain Default to 9dB/Refer to 4.1.1 Gain Control Description
    SPK+ Speaker positive 4Ω/8Ω ＜3W
    DIN Digital input signal
    BCLK Bit clock input Bit Clock Input
    LRC Frame clock Left/right clock of I2S and LJ mode. Synchronized clock in TDM mode

    Special Pin Function

    4.1.1 Gain Control(Gain)
    • Gain is 15dB when there is a 100K resistor connected between GAIN and GND
    • Gain is 12dB when GAIN is directly connected to GND
    • Gain is 9dB(Default status) when nothing is connected to GAIN
    • Gain is 6dB when GAIN is directly connected to VCC
    • Gain is 3dB when there is a 100k resistor connected between Gain and VCC
    SD Mode
    • Turn off amplifier when SD is connected to GND(Voltage below 0.16V)
    • Output mix channel(Default) when the voltage on SD is between 0.16V to 0.77V, R1 resistance is 680k.
    • Output right channel when the voltage on SD is between 0.77V to 1.4V, R1 resistance is 330K.
    • Output left channel when the voltage on SD is over 1.4V, R1 resistance is 100K

    Channel setting

    pin

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