IN74HC138A

TECHNICAL DATA IN74HC138A 1-of-8 Decoder/Demultiplexer High-Performance Silicon-Gate CMOS The IN74HC138A is identical in pinout to the LS/ALS138. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LS/ALSTTL outputs. The IN74HC138A decodes a three-bit Address to one-of-eight active-low outputs. This device features three Chip Select inputs, two active-low and one active-high to facilitate the demultiplexing, cascading, and chip-selecting 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. Outputs Directly Interface to CMOS, NMOS, and TTL Operating Voltage Range: 2.0 to 6.0 V Low Input Current: 1.0 µA High Noise Immunity Characteristic of CMOS Devices ORDERING INFORMATION IN74HC138AN Plastic IN74HC138AD SOIC TA = -55° to 125° C for all packages PIN ASSIGNMENT LOGIC DIAGRAM FUNCTION TABLE Inputs CS1 CS2 CS3 X X H X H X L X X H H H H H H H H L L L L L L L L L L L L L L L L A2 A1 A0 X X X X X X X X X L L L L H H H H L L H H L L H H L H L H L H L H Outputs Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 H H H H H H H H H H H H H H H H H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L PIN 16 =VCC PIN 8 = GND H = high level (steady state) L = low level (steady state) ...