Description
The CS47L24 is a highly integrated, low-power audio hub for wearable technology and other portable audio devices. It
combines an advanced DSP feature set with a flexible, high-performance audio hub codec.
The CS47L24 digital core combines a dual-core, 300MMAC DSP system, with a variety of power-efficient fixed-function
audio-processing blocks. These are supported by a fully flexible, all-digital mixing and routing engine with sample rate
converters for wide use-case flexibility. The programmable DSP cores support a range of advanced audio processing
features, including multimic noise suppression, acoustic-echo cancellation (AEC), and voice recognition functions. The
Enhanced DRE (eDRE) software is included with the CS47L24; additional software packages can be chosen according
to the requirements of the target application.
Three digital audio interfaces are provided, each supporting a wide range of standard audio sample rates and serial
interface formats. Automatic sample-rate detection enables seamless wideband/narrowband voice-call handover.
The headphone/line output driver provides stereo ground-referenced or mono BTL output. 121dB SNR, and noise levels
as low as 0.8 μVRMS, offer hi-fi quality line or headphone output. A mono Class D output driver is incorporated;
supporting up to 2-W audio output. A signal generator for controlling haptics devices is included; vibe actuators can
connect directly to the Class D speaker output or via an external driver connected to a GPIO output. All inputs, outputs,
and system interfaces can function concurrently.
The CS47L24 supports up to four digital microphone inputs. Microphone activity detection with interrupt is available.
The CS47L24 power, clocking and output driver architectures are all designed to maximize battery life in voice, music,
and standby modes. The CS47L24 is powered from 1.8- and 1.2-V external supplies. Separate MICVDD input can be
supported, for microphone operation above 1.8 V. An additional supply is required for the Class D speaker drivers
(typically direct connection to 4.2-V battery).
Two integrated FLLs provide support for a wide range of system clock frequencies. The CS47L24 is configured using an
SPI™ control interface. The fully CS47L24 differential internal analog architecture, minimal analog signal paths, and onchip RF noise filters ensure a very high degree of noise immunity.
Features
• 300 MIPS, 300MMAC dual-core audio-signal processor
• Enhanced DRE processing (eDRE) for 121dB SNR
• Fixed function signal-processing functions
— Dynamic range control, fully parametric EQs
— Tone, noise, PWM, haptic control signal generators
• Multichannel asynchronous sample-rate conversion
• Integrated multichannel 24-bit hi-fi audio hub codec
— 121-dB SNR headphone playback (48 kHz)
• Four digital microphone inputs (two stereo interfaces)
• Stereo headphone/earpiece/line output driver
— 33 mW into 32-Ω load at 1% THD+N
• Mono 2W Class D speaker output driver
• Three full digital audio interfaces
— Standard sample rates from 8kHz up to 192kHz
— TDM support on all AIFs
• Flexible clocking, derived from MCLKn or AIFn
• Two low-power frequency-locked loops (FLLs) support
reference clocks down to 32 kHz
• Configurable functions on two GPIO pins
• Integrated regulators and charge pumps
• Small W-CSP package, 0.4-mm ball array
Applications
• Portable accessories and wearable technology
• Smartphones and multimedia handsets
• Speech-recognition applications
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