54LS257
54LS257 Description
Quad TRI-STATE 2-to-1 Line Data Selector/Multiplexer
54LS257 Vendor
National Semiconductor
54LS257 Categories
54LS257 Features
  • TRI-STATE versions LS157 and LS158 with same pin-outs
  • Schottky-clamped for significant improvement in A-C performance
  • Provides bus interface from multiple sources in high-performance systems
  • Average propagation delay from data input 12 ns
  • Typical power dissipation LS257B 50 mW LS258B 35 mW
  • Alternate military/aerospace devices (54LS257A/54LS258A) are available. Contact a National Semiconductor Sales Office/Distributor for specifications.
54LS257 Description

    These Schottky-clamped high-performance multiplexers feature TRI-STATE outputs that can interface directly with data lines of bus-organized systems. With all but one of the common outputs disabled (at a high impedance state), the low impedance of the single enabled output will drive the bus line to a high or low logic level. To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels, the output enable circuitry is designed such that the output disable times are shorter than the output enable times.

    This TRI-STATE output feature means that n-bit (paralleled) data selectors with up to 258 sources can be implemented for data buses. It also permits the use of standard TTL registers for data retention throughout the system.

54LS257 Datasheet and Application Notes
ParameterValue
PackageCERDIP
Pins16
StatusFull production
Pricing$2.10
Products related to 54LS257
JM38510/30906BEA   JM38510/30906BFA   

ChipCatalog.com - Your Source of Information About Electronic Components