Achieve high efficiency with a plug-and-play solution in an ultra-small form factor.

Maxim Integrated Korea has released the MAX98357 and MAX98358 digital Class-D audio amplifiers. Designers can achieve high efficiency with Maxim's cost-effective, compact, plug-and-play audio solutions. Despite their ultra-small form factor, they deliver superior sound quality with 3.2W of Class AB audio performance, making them suitable for a wide range of applications.

Traditionally, electronics designers have used analog amplifiers with integrated digital-to-analog converters (DACs) and line driver amplifiers integrated into application processors. This adds to the overall integrated circuit (DI) cost for speaker output and impacts the overall solution form factor size. With the rise of voice-activated consumer devices, designers must achieve the highest audio quality while maintaining a compact, efficient, and low-power design.

The MAX98357 pulse-code modulation (PCM) and MAX98358 pulse-density modulation (PDM) plug-and-play speaker amplifiers feature Maxim's exceptional pinout. They also significantly reduce the number of required components compared to typical analog amplifier designs and come in an ultra-small form factor (1.93mm2 WLP). The solution supports three gain levels with easy connectivity. Plug-and-play simplicity requires a single power supply and automatically configures up to 35 clock configurations and 128 digital audio formats. Thanks to automatic configuration, there is no need to rewrite the base code to configure the design as audio functions are added, eliminating the need for complex I2C programming.

Maxim's amplifiers are more cost-effective than competing solutions, boasting a high Class D efficiency of 92%. Because most customers control digital upstream volume, they can use Maxim's cost-effective Wafer-Level Packaging (WLP) instead of expensive Vertical Interconnect Access (VIA). While competing solutions require internal VIAs, two supply voltages, and at least two external components, Maxim's amplifiers require only one external component (bypass capacitor) and one supply voltage for most applications.

The MAX98357/58 deliver superior sound quality by utilizing digital inputs for noise immunity along with the highest jitter tolerance, which is at least 8dB better than competing solutions. They also provide superior electromagnetic interference (EMI) performance and enable longer speaker and trace runs without the need for external filtering. They also boast the highest dynamic range in their family (103.5dB), industry-leading total harmonic distortion (THD) noise (0.013%), and excellent click-pop performance (-66dBV in shutdown mode) through extensive click-pop reduction circuitry. Additionally, the design can be simplified by supplying only the bit clock (BCLK) and LR clock (LRCLK) of the MAX98357/58 without the master clock (MCLK).

As more applications, such as smart speakers, incorporate multidirectional, multi-channel audio, demand for amplifiers like the MAX98357/58 is expected to continue to grow. These amplifiers can be easily daisy-chained to support speaker arrays (up to eight channels supported by time-division multiplexing (TDM)).

“When evaluating audio components for a cybernetic house project, I look for solutions with the best sound quality and form factor,” said Martin Winston, editor-in-chief of Newstips Bulletin. “The MAX98357 digital PCM input Class-D audio amplifier delivers high quality in a minimal space for a Raspberry Pi or other I2S source.”

“Maxim delivers Class D efficiency and the highest audio quality,” said Greg Mow, business manager for mobile audio solutions at Maxim Integrated. “Our pinout allows us to offer an innovative WLP package, enabling customers to take advantage of ultra-small size and low cost.”