文档介绍：w WM8978
Stereo CODEC with Speaker Driver
DESCRIPTION FEATURES
The WM8978 is a low power, high quality stereo CODEC Stereo CODEC:
designed for portable applications such as multimedia phone, DAC SNR 98dB, THD -84dB (‘A’ weighted @ 48kHz)
digital still camera or digital camcorder. ADC SNR 95dB, THD -84dB (‘A’ weighted @ 48kHz)
On-chip Headphone Driver with ‘capless’ option
The device integrates preamps for stereo differential mics, and - 40mW per channel into 16 / SPKVDD
includes drivers for speakers, headphone and differential or 1W output power into 8 BTL speaker / 5V SPKVDD
stereo line output. External component requirements are - Capable of driving piezo speakers
reduced as no separate microphone or headphone amplifiers - Stereo speaker drive configuration
are required. Mic Preamps:
Advanced on-chip digital signal processing includes a 5-band Stereo Differential or mono microphone Interfaces
equaliser, a mixed signal Automatic Level Control for the - Programmable preamp gain
microphone or line input through the ADC as well as a purely - Psuedo differential inputs with common mode
rejection
digital limiter function for record or playback. Additional digital
filtering options are available in the ADC path, to cater for - Programmable ALC / Noise Gate in ADC path
application filtering such