Download SN54LS42 Datasheet PDF
Motorola Semiconductor
SN54LS42
DESCRIPTION The LS42 decoder accepts four active HIGH BCD inputs and provides ten mutually exclusive active LOW outputs, as shown by logic symbol or diagram. The active LOW outputs facilitate addressing other MSI units with LOW input enables. The logic design of the LS42 ensures that all outputs are HIGH when binary codes greater than nine are applied to the inputs. The most significant input A3 produces a useful inhibit function when the LS42 is used as a one-of-eight decoder. The A3 input can also be used as the Data input in an 8-output demultiplexer application. TRUTH TABLE A0 L H L H L H L H L H L H L H L H A1 L L H H L L H H L L H H L L H H A2 L L L L H H H H L L L L H H H H A3 L L L L L L L L H H H H H H H H 0 L H H H H H H H H H H H H H H H 1 H L H H H H H H H H H H H H H H 2 H H L H H H H H H H H H H H H H 3 H H H L H H H H H H H H H H H H 4 H H H H L H H H H H H H H H H H 5 H H H H H L H H H H H H H H H H 6 H H H H H H L H H H H H H H H H 7 H H H H H H H L H H H H H H H H 8...