SN74LS399 Quadruple 2-Input Multiplexers With Storage |

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Quadruple 2-Input Multiplexers With Storage

Quadruple 2-Input Multiplexers With Storage - SN74LS399


This monolithic quadruple two-input multiplexer with storage provides essentially the equivalent functional capabilities of two separate MSI functions (SN54LS157/SN74LS157 and SN54LS175/SN74LS175) in a single 16-pin package.

When the word-select input is low, word 1 (A1, B1, C1, D1) is applied to the flip-flops. A high input to word select will cause the selection of word 2 (A2, B2, C2, D2). The selected word is clocked to the output terminals on the positive-going edge of the clock pulse.

Typical power dissipation is 37 milliwatts. The SN54LS399 is characterized for operation over the full military range of -55°C to 125°C. The SN74LS399 is characterized for operation from 0°C to 70°C.



  • Single-Rail Outputs on 'LS399
  • Selects One of Two 4-Bit Data Sources and Stores Data Synchronously with System Clock
  • Applications:
    • Dual Source for Operands and Constants in Arithmetic Processor; Can Release Processor Register Files for Acquiring New Data
    • Implement Separate Registers Capable of Parallel Exchange of Contents Yet Retain External Load Capability
    • Universal Type Register for Implementing Various Shift Patterns: Even Has Compound Left-Right Capabilities



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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)
SN74LS399 Order now Decoder
LS     4.75     5.25     4     5     35     13     32     2:1     Standard     8     -0.4     Catalog     0 to 70     PDIP | 16
SO | 16    
16PDIP: 181 mm2: 9.4 x 19.3 (PDIP | 16)
16SO: 80 mm2: 7.8 x 10.2 (SO | 16)    
2     5     0.75     2    
SN54LS399 Samples not available Decoder/Demultiplexer     LS     4.5     5.5     4     5     35     13     32     2:1     Standard     8/-0.4       Military     -55 to 125     CDIP | 16     16CDIP: 135 mm2: 6.92 x 19.56 (CDIP | 16)     2     5     0.75     2