SN74F257

SN54F257, SN74F257 QUADRUPLE 2ĆLINE TO 1ĆLINE DATA SELECTORS/MULTIPLEXERS WITH 3ĆSTATE OUTPUTS SDFS065A − D2932, MARCH 1987 − REVISED OCTOBER 1993 3-State Outputs Interface Directly With System Bus Provides Bus Interface From Multiple Sources in High-Performance Systems Package Options Include Plastic Small-Outline Packages, Ceramic Chip Carriers, and Standard Plastic and Ceramic 300-mil DIPs description The ′F257 is designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems. The 3-state outputs will not load the data lines when the output enable (OE) input is at a high logic level. SN54F257 . . . J PACKAGE SN74F257 . . . D OR N PACKAGE (TOP VIEW) A /B 1 1A 2 1B 3 1Y 4 2A 5 2B 6 2Y 7 GND 8 16 VCC 15 OE 14 4A 13 4B 12 4Y 11 3A 10 3B 9 3Y SN54F257 . . . FK PACKAGE (TOP VIEW) 1A A/B NC VCC OE The SN54F257 is characterized for operation over the full military temperature range of − 55°C to 125°C. The SN74F257 is characterized for operation from 0°C to 70°C. FUNCTION TABLE INPUTS OE A /B A OUTPUT B Y H X X X Z L L L X L L L H X H L H X L L L H X H H 1B 3 2 1 20 19 4 18 4A 1Y 5 17 4B NC 6 16 NC 2A 7 15 4Y 2B 8 14 3A 9 10 11 12 13 2Y GND NC 3Y 3B NC − No internal connection logic symbol† 15 OE 1 A /B 2 1A 3 1B 5 2A 6 2B 11 3A 10 3B 14 4A 13 4B EN G1 1 MUX 1 4 1Y 7 2Y 9 3Y 12 4Y † This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12. Pin numbers sho...