The KK74ACT138 is identical in pinout to the LS/ALS138, HC/HCT138. The KK74ACT138 may be used as a level converter for interfacing TTL or NMOS outputs to High Speed CMOS inputs. The KK74ACT138 decodes a three-bit Address to one-of-eight activelot outputs. This device features three Chip Select inputs, two active-low and one active-high to facilitate the demultiplexing, cascading, and chipselecting functions. The demultiplexing function is accomplished by using the Address inputs to select the desired device output; one of the Chip Selects is used as a data input while the other Chip Selects are held in their active states.