FEATURES

• DAC SNR 99dB (‘A’ weighted), THD -84dB at 48kHz, 3.3V 
• ADC SNR 94dB (‘A’ weighted), THD -82dB at 48kHz, 3.3V 
• Microphone interface (Up to four differential microphones) 
• 1W Speaker driver
  - 1W into 8Ω BTL speaker at <0.1% THD
  - 80dB PSRR @217Hz
  - <1uA leakage with direct battery connection
  - Software-selectable class D or AB mode
  - Filterless connection supported 
• Headphone / ear speaker drivers
  - 40mW output power into 16Ω at 3.3V
  - Fully differential and capless modes supported 
• 4 Mono or stereo differential line outputs 
• Pop/click suppression
• Powerful GPIO functions 
• Ultra-low power consumption
  - 5mW voice call
  - 13mW DAC playback to headphones 
• On-chip PLL provides flexible clocking scheme 
• Sample rates: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48 kHz 
• 65-ball 5x5mm BGA package

The WM8991 is a highly integrated ultra-low power hi-fi CODEC designed for handsets rich in multimedia features such as GPS, mobile TV, digital audio playback and gaming. Ultra-low power and low noise interfaces to many other audio components in the system are provided. 

A powerful 1W speaker driver can operate in class D or AB modes, providing total flexibility to the system designer. Low leakage, high PSRR and pop/click suppression enable direct battery connection for the speaker supply. 

A very highly flexible input configuration supports multiple microphone or line inputs (mono or stereo, single-ended or differential).
Four headphone drivers support fully differential headset drive, providing excellent crosstalk performance and bass response, maximising stereo effects, and allowing the removal of large and expensive headphone capacitors. 

Stereo 24-bit sigma-delta ADCs and DACs provide hi-fi quality audio record and playback, with a flexible digital audio interface supporting most commonly-used clocking schemes. An integrated low power PLL, an alternative DAC interface and TDM support provide additional flexibility. 

The WM8991 is supplied in very small and thin 5x5mm 65-ball BGA package, ideal for portable systems.