Product details

Technology family LS Function Digital Multiplexer Configuration 8:1 Number of channels 1 Operating temperature range (°C) -55 to 125 Rating Military
Technology family LS Function Digital Multiplexer Configuration 8:1 Number of channels 1 Operating temperature range (°C) -55 to 125 Rating Military
CDIP (J) 16 135.3552 mm² 19.56 x 6.92 CFP (W) 16 69.319 mm² 10.3 x 6.73 LCCC (FK) 20 79.0321 mm² 8.89 x 8.89
  • Three-State Versions of '151, 'LS151, 'S151
  • Three State Outputs Interface Directly with System Bus
  • Perform Parallel-to-Serial Conversion
  • Permit Multiplexing from N-Lines to One Line
  • Complementary Outputs Provide True and Inverted Data
  • Fully Compatible with Most TTL Circuits

 

  • Three-State Versions of '151, 'LS151, 'S151
  • Three State Outputs Interface Directly with System Bus
  • Perform Parallel-to-Serial Conversion
  • Permit Multiplexing from N-Lines to One Line
  • Complementary Outputs Provide True and Inverted Data
  • Fully Compatible with Most TTL Circuits

 

These monolithic data selectors/multiplexers contain full on-chip binary decoding to select one-of-eight data sources and feature a strobe-controlled three-state output. The strobe must be at a low logic level to enable these devices. The three-state outputs permit a number of outputs to be connected to a common bus. When the strobe input is high, both outputs are in a high-impedance state in which both the upper and lower transistors of each totem-pole output are off, and the output neither drives nor loads the bus significantly. When the strobe is low, the outputs are activated and operate as standard TTL totem-pole outputs.

To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels, the output control circuitry is designed so that the average output disable time is shorter than the average output enable time. The SN54251 and SN74251 have output clamp diodes to attenuate reflections on the bus line.

 

These monolithic data selectors/multiplexers contain full on-chip binary decoding to select one-of-eight data sources and feature a strobe-controlled three-state output. The strobe must be at a low logic level to enable these devices. The three-state outputs permit a number of outputs to be connected to a common bus. When the strobe input is high, both outputs are in a high-impedance state in which both the upper and lower transistors of each totem-pole output are off, and the output neither drives nor loads the bus significantly. When the strobe is low, the outputs are activated and operate as standard TTL totem-pole outputs.

To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels, the output control circuitry is designed so that the average output disable time is shorter than the average output enable time. The SN54251 and SN74251 have output clamp diodes to attenuate reflections on the bus line.

 

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Technical documentation

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Type Title Date
* Data sheet Data Selectors/Multiplexers With 3-State Outputs datasheet 01 Mar 1988
* SMD SN54LS251 SMD 7601601EA 21 Jun 2016
Selection guide Logic Guide (Rev. AB) 12 Jun 2017
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dec 2015
User guide LOGIC Pocket Data Book (Rev. B) 16 Jan 2007
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004
Application note TI IBIS File Creation, Validation, and Distribution Processes 29 Aug 2002
Application note Designing With Logic (Rev. C) 01 Jun 1997
Application note Designing with the SN54/74LS123 (Rev. A) 01 Mar 1997
Application note Input and Output Characteristics of Digital Integrated Circuits 01 Oct 1996
Application note Live Insertion 01 Oct 1996

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CDIP (J) 16 Ultra Librarian
CFP (W) 16 Ultra Librarian
LCCC (FK) 20 Ultra Librarian

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