National Semiconductor DM74LS257
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 Features Y Y Y Y Y Y TRI-STATE versions LS157 and LS158 with same pinouts Schottky-clamped for significant improvement in A-C performance Provides bus interface from multiple sources in highperformance 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...| Part No. | DM74LS257 |
|---|---|
| Datasheet | DM74LS257 Download |
| Manufacturer |  National Semiconductor |
| Description | TRI-STATE Quad 2-Data Selectors/Multiplexers |
| Buy | Stock & Price |
GENERAL 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 systemFEATURES
Y Y Y Y Y Y TRI-STATE versions LS157 and LS158 with same pinouts Schottky-clamped for significant improvement in A-C performance Provides bus interface from multiple sources in highperformance systems Ave...
