Maxim Integrated Products, Inc. recently introduced a smart amplifier, the MAX98390, which integrates Dynamic Speaker Management (DSM) algorithms to dramatically increase volume, with clearer, richer sound quality and lowest static power consumption in the market today. The Boost Digital Class D DSM Smart Amplifier provides a safer and more stable power rating for microspeakers (up to 5.1W, well above the typical value of 1-3W), giving full play to the system’s audio performance.

Today’s consumer devices are getting smaller and smaller, and more and more applications are starting to adopt micro-speakers. As speakers shrink, loudness or sound pressure level (SPL) decreases while the resonant frequency increases, leading to less bass. By increasing the microspeaker drive to increase the volume and low frequency response, it is easy to cause overheating and excessive diaphragm swing, damaging the microspeaker. MAX98390 solves this challenge by utilizing integrated IV (current and voltage) sense and Maxim’s DSM algorithm to drive speakers to their maximum specified limits, while protecting against over excursion and over-temperature events. DSM’s thermal protection empowers designers to safely push their speakers well beyond their specified power rating enabling the speakers to produce their maximum loudness. DSM’s excursion protection enables designers to drive speakers to their specified excursion limits, producing sound up to two octaves below the resonant frequency limit.

To properly protect the speaker, amplifier algorithms must know the characteristics of the speaker, such as resonant frequency within its enclosure, excursion limit and voice coil thermal limit. Traditionally, designers had to go through the time-consuming and complex characterization process or rely on direct supplier support to characterize their speakers and enclosures. This challenge is further exacerbated as most projects start prototyping with multiple speakers per project, requiring several weeks of supplier support or requiring special equipment and expertise. The MAX98390 significantly reduces the design time through the easy-to-use DSM Sound Studio GUI that allows customers to quickly and easily characterize many speakers. Combined with DSM’s thermal protection, the result is maximum loudness across the significantly extended frequency ranges in minutes, with no complex programming required. To cater to the miniaturization of devices and shrinking batteries, the MAX98390 offers industry-leading peak efficiency at 86 percent, which is even further improved with DSM’s Perceptual Power Reduction (PPR) feature that can yield up to an additional 25 percent efficiency, and the lowest quiescent power consumption of ~24mW, making it the ideal choice for low power devices that need longer battery life.

Key Advantages

  • Louder and Deeper Sound Quality:delivers up to 2.5x loudness (Sound Pressure Level) and up to 2 octaves deeper bass versus conventional 5V amplifiers in a small form factor
  • Ease of Use:includes Maxim’s brand-new DSM Sound Studio software GUI, which enables designers to clearly hear the DSM difference in minutes with the Quick Demo feature, and easily characterize and prototype with their own speakers, significantly reducing design time and work
  • Industry-leading Power Consumption:features lowest quiescent power in the market with ~24mW; offers peak efficiency of 86 percent with boosted Class D Amplifier; and further improves efficiency by up to 25 percent with no loss in audio fidelity with Maxim’s DSM PPR feature
  • Designed for Manufacturability:On-chip DC resistance (Rdc) testing can be used on the production line for quality assurance to ensure speaker is within impedance tolerance

“The MAX98390 smart amplifier was designed to boost audio quality in the smallest form-factor to make it nimble enough to go into any device,” said Greg Mow, business manager for Mobile Audio Solutions at Maxim Integrated. “From providing the most balanced and loudest sound to offering the market’s highest efficiency and ease of design, the MAX98390 enables our customers to deliver a best-in-class, immersive sound experience.”

Availability and Pricing:

  • The MAX98390 is available at Maxim’s website for $1.95; also available from authorized distributors
  • TheMAX98390EVSYS# evaluation kit is available for $200