Here is the complete data book for the 74 series chip, which refers to a series of digital integrated circuits with 74XXX (no longer in use), 74SXXX, 74LSXXX, 74FXXX, 74CXXX, 74HCXXX, 74HCTXXX, 74AXXX, 74ASXXX, 74ACTXXX and other series of chips, for \"XXX\" indicates the type of chip, is a string of numbers (such as 00,08,20,138,245, etc.). 373,573,4066, etc.), as long as the number is the same, its logical function is like the same, but the performance difference. 74 series of corresponding CD4000 series and CC4000 series products, such as CD4011 and 74 hc00 is the same. In SMT packaging 74 series chips will use a simplified identification methods, such as identification of HCT74, actual is 74 HCT74 (double) D flip-flop, ACT245 means 74 ACT245 (double buffer), etc.