SLOS638C November   2011  – June 2022 TPA2015D1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 Operating 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 SpeakerGuard™ Theory of Operation
        1. 9.3.1.1 SpeakerGuard™ With Varying Input Levels
        2. 9.3.1.2 Battery Tracking SpeakerGuard™
      2. 9.3.2 Fully Differential Class-D Amplifier
        1. 9.3.2.1 Advantages of Fully Differential Amplifiers
        2. 9.3.2.2 Improved Class-D Efficiency
      3. 9.3.3 Adaptive Boost Converter
        1. 9.3.3.1 Boost Converter Overvoltage Protection
      4. 9.3.4 Operation With DACs and CODECs
      5. 9.3.5 Filter Free Operation and Ferrite Bead Filters
      6. 9.3.6 Speaker Load Limitation
      7. 9.3.7 Fixed Gain Setting
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
      2. 9.4.2 Battery Tracking SpeakerGuard™ Operation
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 TPA2015D1 With Differential Input Signals
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Boost Converter Inductor Selection
            1. 10.2.1.2.1.1 Inductor Equations
          2. 10.2.1.2.2 Boost Converter Capacitor Selection
          3. 10.2.1.2.3 Components Location and Selection
            1. 10.2.1.2.3.1 Decoupling Capacitors
            2. 10.2.1.2.3.2 Input Capacitors
        3. 10.2.1.3 Application Curves
      2. 10.2.2 TPA2015D1 with Single-Ended Input Signals
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curves
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Decoupling Capacitors
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Component Placement
      2. 12.1.2 Trace Width
      3. 12.1.3 Pad Size
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Device Nomenclature
        1. 13.1.1.1 TPA2015D1 Glossary
        2. 13.1.1.2 Boost Terms
    2. 13.2 Community Resources
    3. 13.3 Trademarks
  14. 14Mechanical, Packaging, and Orderable Information
    1. 14.1 Package Option Addendum
      1. 14.1.1 Packaging Information
      2. 14.1.2 Tape and Reel Information

9.3.6 Speaker Load Limitation

Speakers are non-linear loads with varying impedance (magnitude and phase) over the audio frequency. A portion of speaker load current can flow back into the boost converter output via the Class-D output H-bridge high-side device. This is dependent on the speaker's phase change over frequency, and the audio signal amplitude and frequency content.

Most portable speakers have limited phase change at the resonant frequency, typically no more than 40 or 50 degrees. To avoid excess flow-back current, use speakers with limited phase change. Otherwise, flow-back current could exceed the 10 mA rating of the boost converter voltage clamp and drive the PVOUT voltage above the absolute maximum recommended operational voltage.

Confirm proper operation by connecting the speaker to the TPA2015D1 and driving it at maximum output swing. Observe the PVOUT voltage with an oscilloscope. In the unlikely event the PVOUT voltage exceeds 6.5 V, add a 6.8 V Zener diode between PVOUT and ground to ensure the TPA2015D1 operates properly.

The amplifier has thermal overload protection and decatives if the die temperature exceeds 150°C. It automatically reactivates once die temperature returns below 150°C. Built-in output over-current protection deactivates the amplifier if the speaker load becomes short-circuited. The amplifier automatically restarts within 200 ms after the over-current event. Although the TPA2015D1 Class-D output can withstand a short between OUT+ and OUT-, do not connect either output directly to GND, PVDD, or VBAT as this could damage the device.

CAUTION:

Do not connect OUT+ or OUT- directly to GND, PVDD, or VBAT as this could damage the Class-D output stage.