74HC257 74HCT257 Quad 2-input multiplexer 3-state Rev. 6 26 January 2015 Product data sheet 1. General description The 74HC257 74HCT257 are high-speed Si-gate CMOS devices and are pin compatible with Low-power Schottky TTL (LSTTL). The 74HC257 and 74HCT257 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). 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 74HC257 and 74HCT257 are 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 are: 1Y = OE 1I1 S 1I0 S 2Y = OE 2I1 S 2I0 S 3Y = OE 3I1 S 3I0 S 4Y = OE 4I1 S 4I0 S Except for their non-inverting (true) outputs the 74HC257 74HCT257 are identical to the 74HC258. 2. Features and benefits Non-inverting data path 3-state outputs interface directly with system bus Complies with JEDEC standard no. 7A ESD protection: HBM JESD22-A114F exceeds 2000 V MM JESD22-A115-A exceeds 200 V Multiple package options Specified from 40 Cto+85 C and from 40 Cto+125 C74HC257 74HCT257 NXP Semiconductors Quad 2-input multiplexer 3-state 3. Ordering information Table 1. Ordering information Type number Package Temperature range Name Description Version 74HC257N 40 C to +125 C DIP16 plastic dual in-line package 16 leads (300 mil) SOT38-4 74HCT257N 74HC257D 40 C to +125 C SO16 plastic small outline package 16 leads body width 3.9 mm SOT109-1 74HCT257D 74HC257DB 40 C to +125 C SSOP16 plastic shrink small outline package 16 leads SOT338-1 body width 5.3 mm 74HCT257DB 74HC257PW 40 C to +125 C TSSOP16 plastic thin shrink small outline package 16 leads SOT403-1 body width 4.4 mm 74HCT257PW 4. Functional diagram (1 6 , 08 , , , , , , , D P J Fig 1. Logic symbol Fig 2. IEC logic symbol 74HC HCT257 All information provided in this document is subject to legal disclaimers. NXP Semiconductors N.V. 2015. All rights reserved. Product data sheet Rev. 6 26 January 2015 2 of 18 DDG 2( < < < < *