OVERVIEW
The SM6451BV is a 3-wire serial-controlled electronic variable volume IC for audio applications. It provides electronic volume control for a stereo system (left and right channels), and independent channel attenuation and muting, with greatly enhanced digital zip noise suppression. The chip address function allows up to four SM6451BV devices to be connected and individually controlled over the 3-wire control interface from a single CPU. It is available in 16-pin VSOP packages.

FEATURES
■ Stereo inputs and outputs
■ Attenuation function
    • 2-channel independent control
    • 1.0 dB/step over 80 steps
    • 0 to −80 dB range
■ Mute function
■ 3-wire serial data control (MDT, MCK, MLEN)
■ Chip addressing (up to 4 devices can be connected in parallel)
■ Low noise
    • 0.003 % THD + noise
    • 12 µVrms residual noise
■ 2.5 to 3.6 V single power supply
■ Silicon-gate CMOS process

APPLICATIONS
■ Audio equipment