WM8948: Stereo CODEC with video buffer and touchpanel controller


Description

The WM8948 is a highly integrated low power hi-fi CODEC designed for portable devices such as digital still cameras.

Up to 6 analogue inputs may be connected; a 2-channel digital microphone interface is also provided. Flexible output mixing options support single-ended and differential configurations, with outputs derived from the digital audio paths or from analogue bypass paths. Twin stereo outputs or stereo line and mono BTL headphone/speaker drive may be supported.

Flexible digital mixing and powerful DSP functions are available. Programmable filters and other processes may be applied to the ADC and DAC signal paths simultaneously. The DSP functions include 3D-stereo enhancement, 5 notch filters, 5-band EQ, dynamic range control and the Wolfson ReTune™ feature.

The ReTune™ feature is a sophisticated digital filter that can compensate for imperfect characteristics of the housing, loudspeaker or microphone components in an application. The ReTune™ algorithm can provide acoustic equalisation and selective phase (delay) control of specific frequency bands.

The WM8948 is controlled via a I2C or SPI interface. Additional functions include 4-wire Touch Panel controller, Auxiliary ADC, Digital beep generator, Video buffer, programmable GPIO functions, Frequency Locked Loop (FLL) for flexible clocking support and integrated LDO for low noise supply regulation.

The WM8948 is supplied in 36-ball W-CSP package, ideal for portable systems.

Features

  • Hi-fi audio CODEC
    - 94dB SNR during ADC recording (‘A’ weighted)
    - 98dB SNR during DAC playback (‘A’ weighted)
  • 6 analogue audio inputs
  • Integrated bias reference for electret microphones
  • 2-channel digital microphone interface
  • Powerful digital mixing / DSP functions:
    - 3D-stereo enhancement
    - 5-notch filters
    - 5-band equalizer (EQ)
    - ReTune™ parametric filter
    - Dynamic range control and noise gate
    - Low-pass/High-pass filters
    - Direct Form 1 (DF1) programmable digital filter
  • Digital beep generator
  • 4 analogue audio outputs
  • Stereo line output
  • Mono BTL headphone/speaker output driver
  • I2S digital audio interface - sample rates 8kHz to 48kHz
  • Frequency Locked Loop (FLL) frequency conversion / filter
  • Video buffer function
  • 4-wire Touch Panel interface controller
  • Auxiliary ADC for DC measurement or battery monitoring
  • Integrated LDO low-noise voltage regulator
  • 36-ball W-CSP package (2.96 x 3.06 x 0.7mm, 0.5mm pitch)

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