器件名称:
74HC257D
功能描述:
Quad 2-input multiplexer 3-state
文件大小:
80.07KB 共13页
简 介:
INTEGRATED CIRCUITS DATA SHEET For a complete data sheet, please also download: The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications The IC06 74HC/HCT/HCU/HCMOS Logic Package Information The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines 74HC/HCT257 Quad 2-input multiplexer; 3-state Product specication Supersedes data of September 1993 File under Integrated Circuits, IC06 1998 Sep 30 Philips Semiconductors Product specication Quad 2-input multiplexer; 3-state FEATURES Non-inverting data path 3-state outputs interface directly with system bus Output capability: bus driver ICC category: MSI GENERAL DESCRIPTION The 74HC/HCT257 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC/HCT257 have four identical 2-input multiplexers with 3-state outputs, which select 4 bits of data from two sources and are controlled by a common data select input (S). 74HC/HCT257 The data inputs from source 0 (1I0 to 4I0) are selected when input S is LOW and the data inputs from source 1 (1I1 to 4I1) are selected when S is HIGH. Data appears at the outputs (1Y to 4Y) in true (non-inverting) form from the selected inputs. The “257” is the logic implementation of a 4-pole, 2-position switch, where the position of the switch is determined by the logic levels applied to S. The outputs are forced to a high impedance OFF-state when OE is HIGH. The logic equations for the outputs a……
