As devices continue to shrink and customers demand ever sleeker products, Maxim Integrated introduces the MAX98390 smart amplifier with integrated Dynamic Speaker Management (DSM) algorithm to efficiently deliver louder, clearer, richer sound at the lowest quiescent power in the market. The boosted, digital Class D DSM smart amplifier unleashes a system’s full audio potential by safely driving higher power levels (up to 5.1W) into tiny speakers typically rated for much lower power between 1 to 3W.
The miniaturization of consumer devices requires speakers to fit within smaller form factors, which has led to more applications moving towards the use of micro speakers. As speakers shrink, loudness or sound pressure level (SPL) decreases while the resonant frequency increases, leading to less bass. Driving the speakers harder to increase loudness and bass response can easily damage the micro speakers through overheating and over excursion. 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
Availability and Pricing
- The MAX98390 is available at Maxim’s website for $1.95; also available from authorized distributors
- The MAX98390EVSYS# evaluation kit is available for $200
