Boosted Amplifier Brings Immersive Mobile Audio Experience


Cirrus Logic’s CS35L45 Boosted Amp Gives Consumers a New Level of Audio Enjoyment when using Speaker Mode

As consumers increasingly turn to their phone’s internal speakers to enjoy music, podcasts, movies and gaming, Cirrus Logic has introduced its newest flagship CS35L45 boosted amplifier for a richer, more immersive audio experience from smartphones, tablets and mobile gaming devices. Cirrus Logic’s CS35L45 smart power amp delivers higher excursion for high-peak loudness, improved dynamic range for more punch and bass precision, less noise and audible artifacts, and more tonal balance at all volume levels – enabling mobile device manufacturers to push audio performance to new industry benchmarks.

The Cirrus Logic CS35L45 is a 15 V smart boosted Class D audio amplifier with DSP that 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 spending on upgrading the device’s speakers. Among its features are speaker protection and adaptive battery management that drive higher output power in all battery conditions, resulting in up to 30 percent higher peak loudness compared to Cirrus Logic’s previous generation boosted amplifier.

According to a recent user survey conducted by SAR Insight & Consulting for Cirrus Logic, 40 percent of consumers have increased their use of speaker mode over the past 12 months. The global survey shows that as more people work from home during the pandemic, they are increasingly using smartphone speakers to watch and share video via social media, participate in video calls and listen to podcasts or music while multitasking, or simply to create a better atmosphere. These are all factors driving consumers’ desire for better audio quality from their smartphones.

Higher Loudness, Improved Dynamic Range, Longer Battery Life

The CS35L45 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. Since it has the ability to 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 Cirrus Logic CS35L45 smart power amplifier is currently 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. More information on the Cirrus Logic CS35L45 15 V boosted audio amplifier is available at  Cirrus Logic's site.