SLOS993A March   2018  – June 2018 TPA3138D2

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      TPA3138 Layout with Ferrite Beads
  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  Analog Gain
      2. 9.3.2  SD/FAULT Operation
      3. 9.3.3  PLIMIT
      4. 9.3.4  Spread Spectrum and De-Phase Control
      5. 9.3.5  GVDD Supply
      6. 9.3.6  DC Detect
      7. 9.3.7  PBTL Select
      8. 9.3.8  Short-Circuit Protection and Automatic Recovery Feature
      9. 9.3.9  Over-Temperature Protection (OTP)
      10. 9.3.10 Over-Voltage Protection (OVP)
      11. 9.3.11 Under-Voltage Protection (UVP)
    4. 9.4 Device Functional Modes
      1. 9.4.1 MODE_SEL = LOW: BD Modulation
      2. 9.4.2 MODE_SEL = HIGH: Low-Idle-Current 1SPW Modulation
  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 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PWP|28
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10.2.2.3 When to Use an Output Filter for EMI Suppression

The TPA3138D2 device has been tested with a simple ferrite bead filter for a variety of applications including long speaker wires up to 100 cm and high power. The TPA3138D2 EVM passes FCC Class B specifications under these conditions using twisted speaker wires. The size and type of ferrite bead can be selected to meet application requirements. Also, the filter capacitor can be increased if necessary with some impact on efficiency.

There may be a few circuit instances where it is necessary to add a complete LC reconstruction filter. These circumstances might occur if there are nearby circuits which are sensitive to noise. In these cases a classic second order Butterworth filter similar to those shown in the figures below can be used.

Some systems have little power supply decoupling from the AC line but are also subject to line conducted interference (LCI) regulations. These include systems powered by "wall warts" and "power bricks." In these cases, LC reconstruction filters can be the lowest cost means to pass LCI tests. Common mode chokes using low frequency ferrite material can also be effective at preventing line conducted interference.

TPA3138D2 ai_lc_out3_los469.gifFigure 22. Typical Ferrite Chip Bead Filter (Chip Bead Example: NFZ2MSM series from Murata)
TPA3138D2 ai_lc_out2_los469.gifFigure 23. Typical LC Output Filter, Cutoff Frequency of 27 kHz, Speaker Impedance = 8 Ω
TPA3138D2 ai_lc_4ohm_los469.gifFigure 24. Typical LC Output Filter, Cutoff Frequency of 27 kHz, Speaker Impedance = 6 Ω