Product details

Technology family LS Supply voltage (min) (V) 4.75 Supply voltage (max) (V) 5.25 Number of channels 4 IOL (max) (mA) 24 Supply current (max) (µA) 22000 IOH (max) (mA) -2.6 Input type Bipolar Output type 3-State Features High speed (tpd 10-50ns), Input clamp diode Rating Catalog Operating temperature range (°C) 0 to 70
Technology family LS Supply voltage (min) (V) 4.75 Supply voltage (max) (V) 5.25 Number of channels 4 IOL (max) (mA) 24 Supply current (max) (µA) 22000 IOH (max) (mA) -2.6 Input type Bipolar Output type 3-State Features High speed (tpd 10-50ns), Input clamp diode Rating Catalog Operating temperature range (°C) 0 to 70
PDIP (N) 14 181.42 mm² 19.3 x 9.4 SOIC (D) 14 51.9 mm² 8.65 x 6 SOP (NS) 14 79.56 mm² 10.2 x 7.8 SSOP (DB) 14 48.36 mm² 6.2 x 7.8
  • Quad Bus Buffers
  • 3-State Outputs
  • Separate Control for Each Channel

The SN54125, SN54126, SN74125, SN74126, and SN54LS126A are obsolete and are no longer supplied.

  • Quad Bus Buffers
  • 3-State Outputs
  • Separate Control for Each Channel

The SN54125, SN54126, SN74125, SN74126, and SN54LS126A are obsolete and are no longer supplied.

These bus buffers feature three-state outputs that, when enabled, have the low impedance characteristics of a TTL output with additional drive capability at high logic levels to permit driving heavily loaded bus lines without external pullup resistors. When disabled, both output transistors are turned off, presenting a high-impedance state to the bus so the output will act neither as a significant load nor as a driver. The ’125 and ’LS125A devices’ outputs are disabled when G\ is high. The ’126 and ’LS126A devices’ outputs are disabled when G is low.

These bus buffers feature three-state outputs that, when enabled, have the low impedance characteristics of a TTL output with additional drive capability at high logic levels to permit driving heavily loaded bus lines without external pullup resistors. When disabled, both output transistors are turned off, presenting a high-impedance state to the bus so the output will act neither as a significant load nor as a driver. The ’125 and ’LS125A devices’ outputs are disabled when G\ is high. The ’126 and ’LS126A devices’ outputs are disabled when G is low.

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Technical documentation

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Type Title Date
* Data sheet Quadruple Bus Buffers With 3-State Outputs datasheet (Rev. A) 06 Feb 2002
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

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

14-24-LOGIC-EVM — Logic product generic evaluation module for 14-pin to 24-pin D, DB, DGV, DW, DYY, NS and PW packages

The 14-24-LOGIC-EVM evaluation module (EVM) is designed to support any logic device that is in a 14-pin to 24-pin D, DW, DB, NS, PW, DYY or DGV package,

User guide: PDF | HTML
Not available on TI.com
Simulation model

SN74LS125A Behavioral SPICE Model

SDLM049.ZIP (7 KB) - PSpice Model
Simulation model

SN74LS125A IBIS Model

SDLM017.ZIP (11 KB) - IBIS Model
Package Pins CAD symbols, footprints & 3D models
PDIP (N) 14 Ultra Librarian
SOIC (D) 14 Ultra Librarian
SOP (NS) 14 Ultra Librarian
SSOP (DB) 14 Ultra Librarian

Ordering & quality

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Information included:
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