iu ch deltaL k thut bin i tn hiu tng t thnh cc bit. K thu t ny c th chia thnh hai bc l ly mu v m ha tn hi u tng t , c nhiu im tng ng vi k thu t PCM vn tr nn rt thng d ng. u im ca iu ch . Delta l cc mch in ti cc b iu ch v gii iu ch li n gin hn rt nhiu so v i cc mch ca PCM. Mt vi nhc im ca i u ch Delta (vn c hiu l iu ch Delta tuy n tnh) cng c ci thin khi s dng hai k thut ci tin l Delta-Sigma v Delta thch nghi. iu ch Delta tuyn tnh

Hnh 1 : S nguyn l ca mt h thng truyn thng dng iu ch Delta tuyn tnh. Mt my pht to xung Pi(t) cung cp xung ly mu cho b iu ch vi chu k . Tn hi u (t) c a ti b iu ch ch nhn 2 gi tr dng hoc m. Li ra Po(t) c xc nh bng cch nhn chui Pi(t) vi +1 (khi (t) ln hn 0) hoc -1(khi (t) nh hn 0).Tn hi u Po(t) c a ti b tch phn c li ra l s-(t) . Tn hiu ny c dng bc thang, chnh l c lng ca tn hiu tng t s(t) (xem hnh 1.2). Tn hiu s(t) v s-(t) c a ti mt b so snh c li ra l dng ( (t) >0) nu s-(t) >s(t) hoc li ra l m ((t)