SN54-74LS155 PDF File ( Datasheet )

DUAL 1-OF-4 DECODER, DEMULTIPLEXER The SN54 , 74LS155 and SN54 , 74LS156 are high speed Dual 1-of-4 Decoder, Demultiplexers. These devices have two decoders with common 2-bit Address inputs and separate gated Enable inputs. Decoder “a” has an Enable gate with one active HIGH and one active LOW input. Decoder “b” has two active LOW Enable inputs. If the Enable functions are satisfied, one output of each decoder will be LOW as selected by the address inputs. The LS156 has open collector