SLOS907C April   2015  – December 2017 TPA3144D2

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Gain Setting via GAIN Pin
      2. 9.3.2  SD Operation
      3. 9.3.3  Gain Limit Control, LIMTHRES and LIMRATE
      4. 9.3.4  SPEAKERGUARD Automatic Gain Limit, AGL
      5. 9.3.5  Thermal Foldback, TFB
      6. 9.3.6  PLIMIT
      7. 9.3.7  LIMTHRES
      8. 9.3.8  Spread Spectrum and De-Phase Control
      9. 9.3.9  GVDD Supply
      10. 9.3.10 DC Detect
      11. 9.3.11 PBTL Select
      12. 9.3.12 Short-Circuit Protection and Automatic Recovery Feature
      13. 9.3.13 Thermal Protection
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Design Requirements
        1. 10.2.1.1 PCB Material Recommendation
        2. 10.2.1.2 PVCC Capacitor Recommendation
        3. 10.2.1.3 Decoupling Capacitor Recommendations
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Ferrite Bead Filter Considerations
        2. 10.2.2.2 Efficiency: LC Filter Required with the Traditional Class-D Modulation Scheme
        3. 10.2.2.3 When to Use an Output Filter for EMI Suppression
        4. 10.2.2.4 Input Resistance
        5. 10.2.2.5 Input Capacitor, Ci
        6. 10.2.2.6 BSN and BSP Capacitors
        7. 10.2.2.7 Differential Inputs
        8. 10.2.2.8 Using Low-ESR Capacitors
      3. 10.2.3 Application Performance Curves
        1. 10.2.3.1 EN55013 Radiated Emissions Results
        2. 10.2.3.2 EN55022 Conducted Emissions Results
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Decoupling, CS
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.4 SPEAKERGUARD Automatic Gain Limit, AGL

The TPA3144D2 has a built-in SpeakerGuard AGL to limit excessive output voltage to a non clipping output signal. When an excessive level input signal is sent to TPA3144D2, the SpeakerGuard AGL will automatically reduce the amplifier gain to maintain maximum unclipped output signal to preserve high audio quality and to protect the attached speaker from excessive power. The AGL works with a fast attack speed and a slower release speed to achieve maximum protection and a minimum number of audible artifacts.

TPA3144D2 AGC_Levels.gifFigure 17. AGL Attack and Release Thresholds

When the input level multiplied by the TPA3144D2 closed loop gain exceeds the limiter threshold set by the LIMTHRES pin voltage, the TPA3144D2 closed loop gain is reduced by a single or by multiple 0.5-dB steps until the output signal voltage gets below the level set by the LIMTHRES pin voltage, or if a –12.0-dB gain reduction limit is reached. When the output voltage gets below the release threshold, the TPA3144D2 closed loop gain is increased by a single or by multiple 0.5-dB steps until the release threshold is reached, or the closed loop gain is at its nominal closed loop gain level. The AGL gain adjustment is applied with a ramp speed selectable by the LIMRATE pin setting.

TPA3144D2 AGC_Ramp.gifFigure 18. AGL Attack and Release Slopes