Stereo I2S Audio Amplifier - How it works
MAX98357A
MAX98357A is an easy-to-use digital PCM input Class D amplifier with Class AB audio performance. It supports standard I2S digital audio data, eliminating the need for and external master clock (MCLK) signal that would typically be used for PCM communication. The amplifier supports sample rates from 8kHz to 96kHz using 16, 24, 32-bit audio data. It delivers up to 3.2 watts of power into a 4Ω speaker at 5V with 92% efficiency and low distortion (0.013% THD+N at 1kHz). It can be configured to output the left channel, right channel, or mixed (L/2 + R/2) signal for both mono and stereo configurations. The amplifier supports single-supply operation (2.5V to 5.5V).
Datasheet
For an in-depth look at technical specifications, refer to the official MAX98357A Datasheet:
MAX98357A Datasheet
Detailed technical documentation for the MAX98357A Class D Amplifier
How It Works
MAX98357A takes a digital audio signal in I2S format, that incoming signal is then processed by a built-in DAC (digital-to-analog converter) inside the chip and further amplified by a Class D output stage. The filterless (output connects straight to the speaker without external filters) Class D amplifier offers much higher efficiency than Class AB amplifier due to the switching operation of the output stage transistors, delivering power efficiently with little heat. The amplifier automatically detects the audio format and sample rate. Additionaly, the IC offers custom gain selection to modify full-scale output of the DAC.