The SM6451A/B 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 SM6451A/B devices to be connected and individually controlled over the 3-wire control interface from a single CPU.

Block Diagram


  • Stereo inputs and outputs
  • Attenuation function
    2-channel independent control
    1dB/step over 80 steps
  • Mute function
  • 3-wire serial data control (MDT, MCK, MLEN)
  • Chip addressing (up to 4 devices can be connected in parallel)
  • Supply voltage range
    SM6451A:4.5V to 5.5V
    SM6451B:2.5V to 3.6V
  • Package:TSSOP-16-050044-2


  • Audio equipment


6451A_ND14016E00(210.9 KB) 6451B_ND14017E00(179.1 KB)

Application Note

nk9903be(99.8 KB)