74HC251N NXP

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/HCT251 8-input multiplexer 3-state December 1990 Product specication File under Integrated Circuits, IC06Philips Semiconductors Product specication 8-input multiplexer 3-state 74HC/HCT251 FEATURES The 74HC/HCT251 are the logic implementations of single-pole 8-position switches with the state of three True and complement outputs select inputs (S ,S ,S ) controlling the switch positions. 0 1 2 Both outputs are 3-state for further multiplexer Assertion (Y) and negation (Y) outputs are both provided. expansion The output enable input (OE) is active LOW. The logic function provided at the output, when activated, is: Multifunction capability Permits multiplexing from n-lines to one line Y= OE.(I .S .S .S + I .S .S .S + 0 0 1 2 1 0 1 2 + I .S .S .S + I .S .S .S + 2 0 1 2 3 0 1 2 Output capability: standard + I .S .S .S + I .S .S .S + 4 0 1 2 5 0 1 2 I category: MSI CC + I .S .S .S + I .S .S .S ) 6 0 1 2 7 0 1 2 Both outputs are in the high impedance OFF-state (Z) GENERAL DESCRIPTION when the output enable input is HIGH, allowing multiplexer expansion by tying the outputs. The 74HC/HCT251 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. QUICK REFERENCE DATA GND = 0 V T = 25 C t = t = 6 ns amb r f TYPICAL SYMBOL PARAMETER CONDITIONS UNIT HC HCT t / t propagation delay C = 15 pF V = 5 V PHL PLH L CC I to Y 15 19 ns n I toY1719ns n S to Y 20 20 ns n S toY2121ns n C input capacitance 3.5 3.5 pF I C power dissipation capacitance per package notes 1 and 2 44 46 pF PD Notes 1. C is used to determine the dynamic power dissipation (P in W): PD D 2 2 P = C V f + (C V f ) where: D PD CC i L CC o f = input frequency in MHz i f = output frequency in MHz o 2 (C V f ) = sum of outputs L CC o C = output load capacitance in pF L V = supply voltage in V CC 2. For HC the condition is V = GND to V I CC For HCT the condition is V = GND to V - 1.5 V I CC ORDERING INFORMATION See 74HC/HCT/HCU/HCMOS Logic Package Information. December 1990 2