Cirrus Logic Offers Digital PA for Battery-Powered Devices

By Rich Nass

Executive Vice President

Embedded Computing Design

May 12, 2021


Cirrus Logic Offers Digital PA for Battery-Powered Devices

Research says that users are playing music, podcasts, movies, and gaming directly on their handsets, without the use of an external audio device.

To that end, Cirrus Logic has introduced its CS35L45 boosted amplifier for a richer audio experience from smartphones, tablets, and mobile gaming devices. The CS35L45 smart power amp offers high-peak loudness, improved dynamic range for more bass precision, less noise and audible artifacts, and more tonal balance at all volume levels.

The CS35L45 15-V smart boosted Class D audio amplifier with DSP can be easily integrated into a stereo or multi-speaker playback solution for next-generation high-end mobile devices, as well as improve performance in mid-tier devices without having to upgrade the device’s speakers. Among its features are speaker protection and adaptive battery management that drive higher output power in all battery conditions.

The smart power amp features 7-W output power capability and 15-V overboost to enable higher peak power at all frequencies, resulting in more tonal balance at all volume levels, better dynamics, and more spatial range and timbre. Because it can draw high levels of current from the battery, the CS35L45 is “system aware” with built-in battery current and voltage monitoring that delivers high output power but only when required to reproduce the source audio content. The CS35L45 amp’s proprietary adaptive battery management technology helps to “look ahead” to sudden audio signal spikes in order to protect the battery, prevent pumping and clipping, and maximize the audio performance at all volume levels, with no audible artifacts.

The Y-bridge output driver on CS35L45 allows for higher efficiency in receiver and speaker modes for longer battery life. Next-generation, more accurate speaker protection algorithms push speakers to their maximum limits while keeping them within safe limits. On-chip DSP firmware features include equalization and psychoacoustic enhancements that maximize performance from small speakers. The result is top acoustic performance for stereo smartphones that approaches the loudness and sound quality of portable speakers, without sacrificing battery power.

The device is shipping in production volumes in a commercial-grade 0.4-mm pitch, 36-ball wafer-level chip scale package for operation from -40°C to +85°C.

Richard Nass’ key responsibilities include setting the direction for all aspects of OSM’s ECD portfolio, including digital, print, and live events. Previously, Nass was the Brand Director for Design News. Prior, he led the content team for UBM’s Medical Devices Group, and all custom properties and events. Nass has been in the engineering OEM industry for more than 30 years. In prior stints, he led the Content Team at EE Times,, and TechOnLine. Nass holds a BSEE degree from NJIT.

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