SmartHIFI Smart Codec With Advanced Audio Features for Mid-Tier Smartphones

The CS47L15 is a cost optimized smart audio codec with expanded audio features, such as "always on" voice activation, enhanced karaoke (KTV) and virtual stereo for smartphones beyond flagship models. Pro-audio filters enable high fidelity headphone and speaker playback, and low power analog and digital interfaces provide flexible support of the DSP core to enable advanced audio processing functions such as speaker protection and acoustic echo cancellation (AEC). A fully integrated audio subsystem featuring Cirrus Logic's proprietary SmartHIFI ™ offers high resolution HD audio playback, and a low output impedance offers natural audio reproduction independent of the headphone make and model. A 30 mW stereo headphone/earpiece/line output driver provides ground-referenced output with noise levels as low as 0.45 VRMS and just 0.1% total harmonic distortion (THD+N). A 2.5 W Class D driver can enable an extended stereo region for the earpiece speaker with two channels of stereo PDM output to match the louder boosted amplifier. The device is powered from 1.8 V and 1.2 V supplies, and the power, clocking, and output driver architectures are designed to maximize battery life in voice, music and standby modes. Wideband noise reduction and speech enhancement are also provided.



Smart Codecs, Audio DSPs


  • 150 MIPS, 150 MMAC audio-signal processor
    • Fixed functions include dynamic range control, fully parametric EQs, tone, noise, PWM, haptic control signal generators
  • Integrated multi-channel 24-bit hi-fi audio hub codec featuring SmartHIFI™
    • Low distortion: 98 dB SNR mic input (48 kHz)
    • Low noise: 127 dB SNR headphone playback (48 kHz)
    • High dynamic range: 115 dB headphone, referenced to 1 VRMS
    • Linearity: >100 dB THD
    • Transparent frequency and phase response
      • ±0.003 dB
      • Low headphone amp output impedance maintains flatness even when driving complex impedance loads
  • Transparent time domain response: pro audio hi-fi filters (based on WM8741 pro audio DAC)
  • "Always on" low current consumption
    • Low power mode A/D converters enable low power when using analog mics
  • Up to four analog or four digital microphone inputs (speaker-monitoring input path)
  • Three full digital audio interfaces
    • Standard sample rates from 8 to 192 kHz
    • TDM support on all AIFs
  • Advanced clocking architecture
    • FLL(s) generate all clocks needed, internal and external
    • To/from any reference from 32 kHz – 27 MHz with no buffering/streaming gap during swap
    • Powerful sample rate conversion
    • Lowest possible power for all use cases
    • Natural speech recognition with nopause/prompt
    • Simplified software integration
    • Jitter-free audio
  • Compact WLCSP package with 0.4 mm staggered 70-ball array

Parametric Specifications

Not Recommended for New Designs


For more information about Cirrus Logic's Hi-Fi product line, visit the Hi-Fi Audio page.

Software and Tools

CS47L15 Setup

Feb 11, 2021, Rev 1.0.41 : 7.9Mb


Comprehensive Solutions