A CMOS digitally controlled audio attenuator for Hi-Fi systems

Describes an audio attenuator designed for use in digitally controlled Hi-Fi systems. The circuit is fabricated with a thin film on CMOS process and has a dynamic range of 0 to -88.5 dB in 1.5 dB steps. Total harmonic distortion for the complete circuit is typically -87 dB and wide-band signal/noise ratio is typically -86 dB.