SCLS885 December   2022

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions (1)
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics
    6. 6.6  Switching Characteristics - VCC = 2.5 V ± 0.25 V
    7. 6.7  Switching Characteristics - VCC = 3.3 V ± 0.3 V
    8. 6.8  Switching Characteristics - VCC = 5 V ± 0.5 V
    9. 6.9  Operating Characteristics
    10. 6.10 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Standard CMOS Inputs
      2. 8.3.2 Balanced CMOS Push-Pull Outputs
      3. 8.3.3 Partial Power Down (Ioff)
      4. 8.3.4 Wettable Flanks
      5. 8.3.5 Clamp Diode Structure
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Power Considerations
      2. 9.2.2 Input Considerations
      3. 9.2.3 Output Considerations
      4. 9.2.4 Detailed Design Procedure
      5. 9.2.5 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.1 Overview

The SN74LV138A-Q1 devices are 3-line to 8-line decoders/demultiplexers designed for 2 V to 5.5 V VCC operation.

These devices are designed for high-performance memory-decoding or data-routing applications requiring very short propagation delay times. In high-performance memory systems, these decoders can be used to minimize the effects of system decoding. When employed with high-speed memories utilizing a fast enable circuit, the delay times of these decoders and the enable time of the memory usually are less than the typical access time of the memory. This means that the effective system delay introduced by the decoder is negligible.

The conditions at the binary-select inputs (A0, A1, A2) and the three enable inputs (G2, G0, G1) select one of eight output lines. The two active-low (G0, G1) and one active-high (G2) enable inputs reduce the need for external gates or inverters when expanding. A 24-line decoder can be implemented without external inverters and a 32-line decoder requires only one inverter. An enable input can be used as a data input for demultiplexing applications.

These devices are fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the devices when they are powered down.