The WM8978 is a low power stereo codec with integrated pre-amps for stereo differential mics and includes drivers for speakers, headphone and differential or stereo line output. External component requirements are reduced as no separate microphone or headphone amplifiers are required. Advanced on-chip digital signal processing includes a five-band equalizer, a mixed-signal automatic level control for the microphone or line input through the A/D converter, as well as a purely digital limiter function for record or playback. Additional digital filtering options are available in the ADC path to provide application filtering such as ‘wind noise reduction.’ The WM8978 codec can operate as a master or a slave. An internal PLL can generate all required audio clocks for the codec from common reference clock frequencies, such as 12 and 13 MHz. Individual sections of the chip can also be powered down under software control.
Features
Stereo Codec:
DAC SNR 98 dB, THD -84 dB (’A’ weighted @ 48kHz)
ADC SNR 95 dB, THD -84 dB (’A’ weighted @ 48kHz)
On-chip headphone driver with ’capless’ option
40mW output power into 16W / 3.3V SPKVDD
1W output power into 8W BTL speaker / 5V SPKVDD
Capable of driving piezo speakers
Stereo speaker drive configuration
Mic Preamps:
Stereo differential or mono microphone interfaces
Programmable preamp gain
Psuedo-differential inputs with common mode rejection
Programmable ALC / noise gate in ADC path
Low-noise bias supplied for electret microphones
Other Features:
Enhanced 3-D function for improved stereo separation
Digital playback limiter
5-band equalizer (record or playback)
Programmable ADC high pass filter (wind noise reduction)
Programmable ADC notch filter
Aux inputs for stereo analog input signals or beep
On-chip PLL supporting 12, 13, 19.2MHz and other clocks
Low power, low voltage
2.5V to 3.6V (digital core: 1.62V to 3.6V)
5x5mm 32-pin QFN package
The WM8978 is a low power stereo codec with integrated pre-amps for stereo differential mics and includes drivers for speakers, headphone and differential or stereo line output. External component requirements are reduced as no separate microphone or headphone amplifiers are required. Advanced on-chip digital signal processing includes a five-band equalizer, a mixed-signal automatic level control for the microphone or line input through the A/D converter, as well as a purely digital limiter function for record or playback. Additional digital filtering options are available in the ADC path to provide application filtering such as ‘wind noise reduction.’ The WM8978 codec can operate as a master or a slave. An internal PLL can generate all required audio clocks for the codec from common reference clock frequencies, such as 12 and 13 MHz. Individual sections of the chip can also be powered down under software control.
Features
Stereo Codec:
- DAC SNR 98 dB, THD -84 dB (’A’ weighted @ 48kHz)
- ADC SNR 95 dB, THD -84 dB (’A’ weighted @ 48kHz)
- On-chip headphone driver with ’capless’ option
- 40mW output power into 16W / 3.3V SPKVDD
- 1W output power into 8W BTL speaker / 5V SPKVDD
- Capable of driving piezo speakers
- Stereo speaker drive configuration
Mic Preamps:
- Stereo differential or mono microphone interfaces
- Programmable preamp gain
- Psuedo-differential inputs with common mode rejection
- Programmable ALC / noise gate in ADC path
- Low-noise bias supplied for electret microphones
Other Features:
- Enhanced 3-D function for improved stereo separation
- Digital playback limiter
- 5-band equalizer (record or playback)
- Programmable ADC high pass filter (wind noise reduction)
- Programmable ADC notch filter
- Aux inputs for stereo analog input signals or beep
- On-chip PLL supporting 12, 13, 19.2MHz and other clocks
- Low power, low voltage
- 2.5V to 3.6V (digital core: 1.62V to 3.6V)
- 5x5mm 32-pin QFN package
