Descrição das sub-famílias: TTL (74xx) TTL standard 74L Low power 74S Schottky 74H High speed 74LS Low power - Schottky 74AS Advanced - Schottky 74ALS Advanced - Low power - Schottky 74F(AST) Fast - (Advanced - Schottky) 74C CMOS 74HC (U) High speed - CMOS 74HCT High speed - CMOS - TTL inputs 74AHC Advanced - High speed - CMOS 74AHCT Advanced - High speed - CMOS - TTL inputs 74FCT Fast - CMOS - TTL inputs 74AC Advanced - CMOS 74ACT Advanced - CMOS - TTL inputs 4000 True CMOS (non-TTL levels)