SN74LS155A Dual 2-Line To 4-Line Decoders/Demultiplexers |

SN74LS155A (ACTIVE) Dual 2-Line To 4-Line Decoders/Demultiplexers

Dual 2-Line To 4-Line Decoders/Demultiplexers - SN74LS155A


These monolithic transistor-transistor-logic (TTL) circuits feature dual 1-line-to-4-line demultiplexers with individual strobes and common binary-address inputs in a single 16-pin package. When both sections are enabled by the strobes, the common binary-address inputs sequentially select and route associated input data to the appropriate output of each section. The individual strobes permit activating or inhibiting each of the 4-bit sections as desired. Data applied to input 1C is inverted at its outputs and data applied at 2C\ is not inverted through its outputs. The inverter following the 1C data input permits use as a 3-to-8-line decoder or 1-to-8-line demultiplexer without external gating. Input clamping diodes are provided on all of these circuits to minimize transmission-line effects and simplify system design.



  • Applications:
    • Dual 2-to 4-Line Decoder
    • Dual 1-to 4-Line Demultiplexer
    • 3-to 8-Line Decoder
    • 1-to 8-Line Demultiplexer
  • Individual Strobes Simplify Cascading for Decoding or Demultiplexing Larger Words
  • Input Clamping Diodes Simplify System Design
  • Choice of Outputs:
    • Totem Pole ('155, 'LS155A)
    • Open-Collector ('156, 'LS156)



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Part number Order Function Technology Family VCC (Min) (V) VCC (Max) (V) Channels (#) Voltage (Nom) (V) F @ nom voltage (Max) (MHz) ICC @ nom voltage (Max) (mA) tpd @ nom Voltage (Max) (ns) Configuration Type IOL (Max) (mA) IOH (Max) (mA) Rating Operating temperature range (C) Package Group Package size: mm2:W x L (PKG) Bits (#) Digital input leakage (Max) (uA) ESD CDM (kV) ESD HBM (kV)
SN74LS155A Order now Decoder
LS     4.75     5.25     2     5     35     10     27     2:4     Standard     8     -0.4     Catalog     0 to 70     PDIP | 16
SOIC | 16
SO | 16    
See datasheet (PDIP)
16SO: 80 mm2: 7.8 x 10.2 (SO | 16)
16SOIC: 59 mm2: 6 x 9.9 (SOIC | 16)    
4     5     0.75     2    
SN54LS155A Samples not available Decoder/Demultiplexer     LS     4.5     5.5     2     5     35     10     27     2:4     Standard     8/-0.4       Military     -55 to 125     CDIP | 16
CFP | 16    
See datasheet (CDIP)
See datasheet (CFP)    
4     5     0.75     2