Source : Free On-Line Dictionary of Computing

Low Voltage Differential
     
         (LVD) A method of driving {SCSI} cables that will
        be formalised in the {SCSI-3} specifications.  LVD uses less
        power than the current differential drive ({HVD}), is less
        expensive and will allow the higher speeds of {Ultra-2 SCSI}.
        LVD requires 3.3 Volts DC instead of 5 Volts DC for HVD.
     
        (1999-02-16)