Maxim’s MAX98390 Smart Amplifier Enhances Micro‑Speaker Performance with Advanced DSM Technology

As devices continue to shrink, consumers demand ever sleeker audio solutions. Maxim Integrated Products responds with the MAX98390 smart amplifier, a digital Class D solution that integrates Dynamic Speaker Management (DSM) to deliver louder, clearer, richer sound while consuming the lowest quiescent power in the market. The boosted amplifier can safely drive micro‑speakers up to 5.1 W, well beyond the typical 1–3 W rating, unlocking the full audio potential of compact systems.

Micro‑speaker miniaturization has increased resonant frequencies and reduced sound‑pressure levels, especially in the bass region. Pushing these tiny drivers harder can quickly lead to overheating or excessive excursion. The MAX98390 mitigates these risks with built‑in current and voltage sensing coupled to Maxim’s proprietary DSM algorithm. Thermal protection allows designers to push speakers close to, or even beyond, their rated power without damage, while excursion protection caps movement to the speakers’ safe limits, enabling audio output up to two octaves below the resonant frequency.

Accurate speaker protection requires knowledge of resonant frequency, excursion limits, and voice‑coil thermal limits. Traditionally, designers spent weeks characterizing each unit or relied on vendor support. The MAX98390 streamlines this process through the DSM Sound Studio GUI, which quickly maps speaker behavior and applies the correct protection parameters. The result is maximum loudness across extended frequency ranges in minutes—no complex firmware tweaks needed.

For battery‑constrained, high‑density devices, the MAX98390 offers industry‑leading peak efficiency of 86 %. Combined with DSM’s Perceptual Power Reduction (PPR), efficiency can rise by an additional 25 %. Coupled with a quiescent power of just ~24 mW, this amplifier is the ideal choice for long‑lasting, low‑power audio applications.