SNAS344F December   2005  – June 2025 LM4674

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Key Specifications
  5. DESCRIPTION
  6. Pin Configuration and Functions
  7. 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. Block Diagrams
  9. 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. 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

Differential Amplifier Explanation

As logic supplies continue to shrink, system designers are increasingly turning to differential analog signal handling to preserve signal to noise ratios with restricted voltage signs. The LM4674 features two fully differential amplifiers. A differential amplifier amplifies the difference between the two input signals. Traditional audio power amplifiers have typically offered only single-ended inputs resulting in a 6dB reduction of SNR relative to differential inputs. The LM4674 also offers the possibility of DC input coupling which eliminates the input coupling capacitors. A major benefit of the fully differential amplifier is the improved common mode rejection ratio (CMRR) over single ended input amplifiers. The increased CMRR of the differential amplifier reduces sensitivity to ground offset related noise injection, especially important in noisy systems.