Maxim MAX98357 and MAX98358 digital-input Class D audio power amplifiers

With the MAX98357 and MAX98358 digital-input Class D audio power amplifiers by Maxim Integrated Products, designers can achieve high efficiency of 92% in a compact plug-and-play solution. The Class D efficient amplifiers deliver 3.2 W of Class AB audio performance for good audio quality and are suitable for a variety of applications.

The MAX98357 pulse-code modulation (PCM) and MAX98358 pulse-density modulation (PDM) plug-and-play speaker amplifiers reduce overall solution size due to Maxim’s clever pin-out and by reducing the number of required components compared to typical analog amplifier designs. These features enable users to take advantage of the company’s wafer-level packaging (WLP) without the need for vertical interconnect access (VIA). Only one external component (bypass capacitor) and one supply voltage is needed for most applications, resulting in a solution size of 1.93 mm² WLP.

The amplifiers feature high dynamic range (103.5 dB), low total harmonic distortion (THD) noise (0.013%), high jitter tolerance and good click-pop performance (-66 dBV out of shutdown) via extensive click-pop reduction circuitry. They also have a digital input for noise immunity, offer good electromagnetic interference (EMI) performance, and allow the use of long traces to the speakers without added external filtering.

The plug-and-play functionality only requires users to connect a single power supply and feed the bit clock (BCLK) and left-right clock (LRCLK) of both the amplifiers, without needing a master clock (MCLK). The amplifiers further simplify designs by auto-configuring for up to 35 different clocking configurations and 128 different digital audio formats. This automatic configuration eliminates complicated I²C programming as there is no longer a need to rewrite base code to configure a design just to add audio functionality.