Max98357a I2S Class D Amplifier takes standard I2S digital audio input, not only decodes it into analog, but also amplifies it directly into a speaker.; Ultra-Efficient
Class D Power: Operates on a low voltage range (DC 2.7V - 5.5V ) with high Class D efficiency, ensuring minimal heat and maximum battery life. Ideal for portable, battery-powered projects like custom smart speakers and handheld audio devices, providing robust sound with low power draw; The MAX98357 MAX98357A I2S 3W Class D Amplifier Breakout for Raspberry Pi, Arduino, and ESP32, this audio power amplifier module seamlessly integrates with microcontrollers and development boards with I2S audio output.; There's a Gain pin that can be manipulated to change the gain. By default, the amp will give you 9dB of gain. By connecting a pullup or pull down resistor, or wiring directly, the Gain pin can be set up to give 3dB, 6dB, 9dB, 12dB or 15dB.; I2S in a digital sound protocol that is used on circuit boards to pass audio data around. Many high end chips and processors manage all of the audio in digital I2S format. To input or output data, three or four pins are used (data in, data out, bit clock and left-right channel select).
Usually, for audio devices, there's a DAC chip that will take I2S in and convert it to analog that can drive a headphone.