WM8753: Voice and audio CODEC


Description

The WM8753L is a low power, high quality stereo Codec with integrated PCM CODEC designed for portable digital telephony applications such as mobile phone, or headset with hi-fi playback capability.

The device integrates dual interfaces to two differentially connected microphones, and includes drivers for speakers, headphone and earpiece. External component requirements are reduced as no separate microphone or headphone amplifiers are required, and Cap-less connections can be made to all loads. Advanced on-chip digital signal processing performs tone control, Bass Boost and automatic level control for the microphone or line input through the ADC. The two ADCs may be used to support Voice noise cancellation in a partnering DSP, or for stereo recording.

The WM8753L hi-fi DAC can operate as a master or a slave, with various master clock frequencies including 12 or 24MHz for USB devices, 13MHz or 19.2MHz for cellular systems, or standard 256fs rates like 12.288MHz and 24.576MHz. Internal PLLs generate all required clocks for both PCM and hi-fi converters. If audio system clocks already exist, the PLLs may be committed to alternative uses.

The WM8753L operates at a nominal supply voltage of 2V, although the digital core can operate at voltages down to 1.42V to save power, and the maximum for all supplies is 3.6 Volts. Different sections of the chip can also be powered down under software control.

Features

  • Hi-Fi DAC: interfaced over I2S type link
  • Audio sample rates:
  • 8, 11.025, 16, 22.05, 24, 32, 44.1, 48,
  • DAC SNR 98dB, THD -84dB (‘A’ weighted @ 48kHz)
  • ADC SNR 95dB, THD -82dB (‘A’ weighted @ 48kHz)
  • On-chip Headphone Driver with cap-less output option
  • - 40mW output power on 16W / 3.3V
  • - with 16W load: SNR 90dB, THD –75dB
  • - with 10kW load: SNR 94dB, THD –90dB
  • On-chip speaker driver with 0.5W into 8R
  • Voice Codec: interfaced over voice interface
  • supports sample rates from 8ks/s to 48ks/s
  • ADC and DAC SNR 82dB, THD -74dB ·
  • Two Differential Microphone Interfaces
  • - Dual ADCs support noise cancellation in external DSP
  • - Programmable ALC / Noise Gate ·
  • Low-noise bias supplied for electret microphones
  • Other features ·
  • On-chip PLLs supporting 12, 13, 19.2MHz and other clocks
  • Cap-less connection options to headphones, earpiece, spkr.
  • Low power, low voltage
  • - 1.8V to 3.6V (digital core: 1.42V to 3.6V)
  • - power consumption <20mW all-on with 2V supplies
  • - <12mW for PCM CODEC operation
  • 7x7x0.9mm QFN package