74LS259D
8-Bit Addressable Latches
12 Stck in Stange / 10,- € Stck = 120,- € Gesamt 202411-004-214 DM74LS259
General Description
These 8-bit addressable latches are designed for general
purpose storage applications in digital systems. Specific
uses include working registers, serial-holding registers,
and active-high decoders or demultiplexers. They are multifunctional
devices capable of storing single-line data in
eight addressable latches, and being a 1-of-8 decoder or
demultiplexer with active-high outputs.
Four distinct modes of operation are selectable by controlling
the clear and enable inputs as enumerated in the function
table. In the addressable-latch mode, data at the datain
terminal is written into the addressed latch. The
addressed latch will follow the data input with all unaddressed
latches remaining in their previous states. In the
memory mode, all latches remain in their previous states
and are unaffected by the data or address inputs. To eliminate
the possibility of entering erroneous data in the
latches, the enable should be held HIGH (inactive) while
the address lines are changing. In the 1-of-8 decoding or
demultiplexing mode, the addressed output will follow the
level of the D input with all other outputs LOW. In the clear
mode, all outputs are LOW and unaffected by the address
and data inputs.
Features
■ 8-Bit parallel-out storage register performs serial-to-par- allel conversion with storage
■ Asynchronous parallel clear
■ Active high decoder
■ Enable/disable input simplifies expansion
■ Direct replacement for Fairchild DM9334
■ Expandable for N-bit applications
■ Four distinct functional modes
■ Typical propagation delay times: Enable-to-output 18 ns Data-to-output 16 ns
Address-to-output 21 ns
Clear-to-output 17 ns
■ Fan-out
IOL (sink current) 8 mA IOH (source current) -0.4 mA
■ Typical ICC 22 mA