Class D Audio Amplifier + Class H Boosted 15 V Converter with Integrated DSP Enables Maximum Loudness, Higher Bass

The CS35L45 is the industry’s most advanced smart boosted amplifier solution for driving maximum loudness in mobile devices without compromising playback audio quality. The IC’s hardware platform combines a mono 6.8 W Class D amplifier with the lowest noise and quiescent power consumption of any amplifier in its class. A digitally controlled Class H inductive boost converter is capable of boosting battery voltages up to 15 V for speaker playback. Speaker protection algorithms enable maximum loudness by allowing the amplifier to safely drive high output power while ensuring that the speaker’s thermal and excursion limits are not exceeded. Audio enhancement algorithms with tuning capabilities provide equalization, compression and psychoacoustic improvements to fine-tune the speaker to improve clarity, loudness and frequency response while preserving the sound quality of the audio. A cutting-edge battery management system adapts to speaker, audio and battery conditions to intelligently regulate battery current without sacrificing loudness or audio quality. The CS35L45 is housed in a 36-ball WLCSP package measuring just 6.5 mm2, which is one of the industry’s smallest packages for a smart audio amplifier.



Audio Amplifiers


  • 15 V supply voltage MAX
  • Integrated DSP with audio enhancement and speaker protection algorithms
  • Cutting-edge battery management system protects battery and system while maintaining volume and quality
  • Audio sample rates from 8-192 kHz, including 44.1 kHz
  • Supports I2S or TDM serial audio
  • 6.8 W @ 1% THD+N into 8 Ω
  • -79 dB THD+N @ 1 W into 8 Ω
  • 5μV Idle-channel noise – lowest in class
  • 0.043 mW idle power – lowest in class
  • 6.5 mm2 36-ball WLCSP package

Parametric Specifications

Description Class D Smart Amp
Vout(V)-Max 15
Output Power (W) @1% THD+N, into 8 ohm 6.8
Boost Class H
Channels Mono
Inputs I²S;
Supply (V) 2.5-5.5
Idle Power Consumption (mW) 0.043
Idle Noise (μVrms) 5
Size (mm²) 6.5
Package 36-ball WLCSP
Pitch (mm) 0.4

Press Releases


Mar 24

Cirrus Logic Smart Boosted Amplifier Brings Immersive Mobile Audio Experience to New Generations of Smartphones, Tablets and Gaming Devices

Cirrus Logic’s CS35L45 Boosted Amp Gives Consumers a New Level of Audio Enjoyment when using Speaker Mode for Music, Podcasts, Video Conference Calls, Movies and Gaming

Mar 24

Smartphone Consumer Usage Survey Shows 40 Percent Increase in Speaker Mode Use as More People Work from Home and Share Social Media During Global Pandemic

Study Conducted by SAR Insight for Cirrus Logic Reveals Increased Video Calling, Sharing of Social Media Content or Simply Creating a Better Atmosphere Are All Factors Driving Consumers’ Desire for Better Audio Quality


Comprehensive Solutions