SN74LS374

ACTIVE

Octal D-Type Edge Triggered Flip-Flops with 3-State Outputs

Product details

Number of channels 8 Technology family LS Supply voltage (min) (V) 4.75 Supply voltage (max) (V) 5.25 Input type Bipolar Output type 3-State Clock frequency (max) (MHz) 35 IOL (max) (mA) 24 IOH (max) (mA) -2.6 Supply current (max) (µA) 40000 Features High speed (tpd 10-50ns) Operating temperature range (°C) 0 to 70 Rating Catalog
Number of channels 8 Technology family LS Supply voltage (min) (V) 4.75 Supply voltage (max) (V) 5.25 Input type Bipolar Output type 3-State Clock frequency (max) (MHz) 35 IOL (max) (mA) 24 IOH (max) (mA) -2.6 Supply current (max) (µA) 40000 Features High speed (tpd 10-50ns) Operating temperature range (°C) 0 to 70 Rating Catalog
PDIP (N) 20 228.702 mm² 24.33 x 9.4 SOIC (DW) 20 131.84 mm² 12.8 x 10.3 SOP (NS) 20 98.28 mm² 12.6 x 7.8 SSOP (DB) 20 56.16 mm² 7.2 x 7.8
  • Choice of Eight Latches or Eight D-Type Flip-Flops in a Single Package
  • 3-State Bus-Driving Outputs
  • Full Parallel Access for Loading
  • Buffered Control Inputs
  • Clock-Enable Input Has Hysteresis to Improve Noise Rejection (’S373 and ’S374)
  • P-N-P Inputs Reduce DC Loading on Data Lines (’S373 and ’S374)

  • Choice of Eight Latches or Eight D-Type Flip-Flops in a Single Package
  • 3-State Bus-Driving Outputs
  • Full Parallel Access for Loading
  • Buffered Control Inputs
  • Clock-Enable Input Has Hysteresis to Improve Noise Rejection (’S373 and ’S374)
  • P-N-P Inputs Reduce DC Loading on Data Lines (’S373 and ’S374)

These 8-bit registers feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. The high-impedance 3-state and increased high-logic-level drive provide these registers with the capability of being connected directly to and driving the bus lines in a bus-organized system without need for interface or pullup components. These devices are particularly attractive for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The eight latches of the ’LS373 and ’S373 are transparent D-type latches, meaning that while the enable (C or CLK) input is high, the Q outputs follow the data (D) inputs. When C or CLK is taken low, the output is latched at the level of the data that was set up.

The eight flip-flops of the ’LS374 and ’S374 are edge-triggered D-type flip-flops. On the positive transition of the clock, the Q outputs are set to the logic states that were set up at the D inputs.

Schmitt-trigger buffered inputs at the enable/clock lines of the ’S373 and ’S374 devices simplify system design as ac and dc noise rejection is improved by typically 400 mV due to the input hysteresis. A buffered output-control (OC) input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.

OC\ does not affect the internal operation of the latches or flip-flops. That is, the old data can be retained or new data can be entered, even while the outputs are off.

These 8-bit registers feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. The high-impedance 3-state and increased high-logic-level drive provide these registers with the capability of being connected directly to and driving the bus lines in a bus-organized system without need for interface or pullup components. These devices are particularly attractive for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The eight latches of the ’LS373 and ’S373 are transparent D-type latches, meaning that while the enable (C or CLK) input is high, the Q outputs follow the data (D) inputs. When C or CLK is taken low, the output is latched at the level of the data that was set up.

The eight flip-flops of the ’LS374 and ’S374 are edge-triggered D-type flip-flops. On the positive transition of the clock, the Q outputs are set to the logic states that were set up at the D inputs.

Schmitt-trigger buffered inputs at the enable/clock lines of the ’S373 and ’S374 devices simplify system design as ac and dc noise rejection is improved by typically 400 mV due to the input hysteresis. A buffered output-control (OC) input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.

OC\ does not affect the internal operation of the latches or flip-flops. That is, the old data can be retained or new data can be entered, even while the outputs are off.

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Technical documentation

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Type Title Date
* Data sheet Octal D-Type Transparent Latches And Edge-Triggered Flip-Flops datasheet (Rev. B) 23 Aug 2002
Application note Power-Up Behavior of Clocked Devices (Rev. B) PDF | HTML 15 Dec 2022
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

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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

SN74LS374 IBIS Model (Rev. A)

SDLM010A.ZIP (6 KB) - IBIS Model
Package Pins CAD symbols, footprints & 3D models
PDIP (N) 20 Ultra Librarian
SOIC (DW) 20 Ultra Librarian
SOP (NS) 20 Ultra Librarian
SSOP (DB) 20 Ultra Librarian

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