SNAS344F December   2005  – June 2025 LM4674

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Key Specifications
  5. 4 DESCRIPTION
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Operating Ratings
    3. 6.3 Electrical Characteristics VDD = 3.6V
    4. 6.4 Typical Performance Characteristics
  8. 7 Block Diagrams
  9. 8 Application Information
    1. 8.1  General Amplifier Function
    2. 8.2  Differential Amplifier Explanation
    3. 8.3  Power Dissipation and Efficency
    4. 8.4  Shutdown Function
    5. 8.5  Single-Ended Audio Amplifier Configuration
    6. 8.6  Audio Amplifier Power Supply Bypassing/Filtering
    7. 8.7  Audio Amplifier Input Capacitor Selection
    8. 8.8  Audio Amplifier Gain Setting
    9. 8.9  Output Filter Considerations
    10. 8.10 Layout Guidelines
    11. 8.11 LM4674TL Demo Board Schematic
    12. 8.12 LM4674TL Demonstration Board Layout
    13. 8.13 LM4674SQ Demo Board Schematic
    14. 8.14 LM4674SQ Demonstration Board Layout
    15. 8.15 Trademarks
  10. 9 Typical Application
  11. 10Development Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Device Nomenclature Boilerplate
  12. 11Receiving Notification of Documentation Updates
  13. 12Electrostatic Discharge Caution
  14. 13Glossary
  15. 14Revision History
  16. 15Mechanical, Packaging, and Orderable Information

Package Options

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

8.3 Power Dissipation and Efficency

The major benefit of a Class D amplifier is increased efficiency versus a class AB amplifier. The efficiency of the LM4674 is attributed to the region of operation of the transistors in the output stage. The Class D output stage acts as current steering switches, consuming negligible amounts of power compared to their Class AB counterparts. Most of the power loss associated with the output stage is due to the IR loss of the MOSFET on-resistance (RDS(ON)), along with switching losses due to gate charge.