DM74AS257N

Supply Voltage - Max : 5.5 V
Supply Voltage - Min : 4.5 V
Number of Bits : 4
Packaging : Tube
Product : Decoders, Encoders, Multiplexers & Demultiplexers
Mounting Style : Through Hole
Package / Case : PDIP-16
Maximum Operating Temperature : + 70 C
Number of Lines (Input / Output) : 1 / 2
Propagation Delay Time : 6 ns at 4.5 V to 5.5 V
Logic Family : 74A


Features:

·  Switching specifications at 50 pF
·  Switching specifications guaranteed over full temperature and VCC range
·  Advanced oxide-isolated, ion-implanted Schottky TTL process
·  Functionally and pin for pin compatible with Schottky,
   low power Schottky, and advanced low power Schottky TTL counterpart
·  Improved AC performance over Schottky, low power
   Schottky, and advanced low power Schottky counterparts
·  3-STATE buffer-type output drive bus lines directly
·  Expand any data input point
·  Multiplex dual data buses
·  General four functions of two variables (one variable is common)
·  Source programmable counters


Pinout




Specifications

Supply Voltage, V_{CC....................................................} 7V
Input Voltage ..............................................................7V
Voltage Applied to Disabled Output......................... 5.5V
Operating Free Air Temperature Range..... 0°C to +70°C
Storage Temperature Range ................-65°C to +150°C
Typical qJA
N Package ........................................................75.0°C/W
Note 1: The "Absolute Maximum Ratings" are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The "Recommended Operating Conditions" table will define the conditions
for actual device operation.


Description

These DM74AS257N data selectors/multiplexers contain inverters and drivers to supply full on-chip data selection to the four 3- STATE outputs that can interface directly with data lines of bus-organized systems. A 4-bit word selected from one of two sources is routed to the four outputs. The DM74AS257 presents true data whereas the DM74AS258 presents inverted data to minimize propagation delay time.

This 3-STATE output feature means that n-bit (paralleled) data selectors with up to 300 sources can be implemented for data buses. It also permits the use of standard TTL registers for data retention throughout the system.

If you want to know more about DM74AS257N, please feel free to contact Seekic.