ZHCSHZ1 April   2018 TPA3126D2

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
    1.     Device Images
      1.      TPA3126 和 TPA3116 空闲电流
      2.      简化应用电路
  4. 修订历史记录
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions
  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 DC Electrical Characteristics
    6. 7.6 AC Electrical Characteristics
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Gain Setting and Master and Slave
      2. 8.3.2  Input Impedance
      3. 8.3.3  Startup and Shutdown Operation
      4. 8.3.4  PLIMIT Operation
      5. 8.3.5  GVDD Supply
      6. 8.3.6  BSPx and BSNx Capacitors
      7. 8.3.7  Differential Inputs
      8. 8.3.8  Device Protection System
      9. 8.3.9  DC Detect Protection
      10. 8.3.10 Short-Circuit Protection and Automatic Recovery Feature
      11. 8.3.11 Thermal Protection
      12. 8.3.12 Device Modulation Scheme
        1. 8.3.12.1 BD Modulation
      13. 8.3.13 Efficiency: LC Filter Required with the Traditional Class-D Modulation Scheme
      14. 8.3.14 Ferrite Bead Filter Considerations
      15. 8.3.15 When to Use an Output Filter for EMI Suppression
      16. 8.3.16 AM Avoidance EMI Reduction
    4. 8.4 Device Functional Modes
      1. 8.4.1 Mono PBTL Mode
      2. 8.4.2 Mono BTL Mode (Single Channel Mode)
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Typical Application
        1. 9.1.1.1 Design Requirements
        2. 9.1.1.2 Detailed Design Procedure
          1. 9.1.1.2.1 Select the PWM Frequency
          2. 9.1.1.2.2 Select the Amplifier Gain and Master/Slave Mode
          3. 9.1.1.2.3 Select Input Capacitance
          4. 9.1.1.2.4 Select Decoupling Capacitors
          5. 9.1.1.2.5 Select Bootstrap Capacitors
        3. 9.1.1.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Mode
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Heat Sink Used on the EVM
  12. 12器件和文档支持
    1. 12.1 器件支持
      1. 12.1.1 开发支持
    2. 12.2 接收文档更新通知
    3. 12.3 相关文档
    4. 12.4 社区资源
    5. 12.5 商标
    6. 12.6 静电放电警告
    7. 12.7 Glossary
  13. 13机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

Ferrite Bead Filter Considerations

Using the Advanced Emissions Suppression Technology in the TPA3126D2, a high efficiency Class-D audio amplifier can be designed while minimizing interference to the surrounding circuits. Designing the amplifier can also be accomplished with only a low-cost ferrite bead filter. In this case the user must carefully select the ferrite bead used in the filter. One important aspect of the ferrite bead selection is the type of material used in the ferrite bead. Not all ferrite material is alike, therefore the user must select a material that is effective in the 10-MHz to 100-MHz range which is key to the operation of the Class-D amplifier. Many of the specifications regulating consumer electronics have emissions limits as low as 30-MHz. The ferrite bead filter should be used to block radiation in the 30-MHz and above range from appearing on the speaker wires and the power supply lines which are good antennas for these signals. The impedance of the ferrite bead can be used along with a small capacitor with a value in the range of 1000-pF to reduce the frequency spectrum of the signal to an acceptable level. For best performance, the resonant frequency of the ferrite bead or capacitor filter should be less than 10-MHz.

Also, the ferrite bead must be large enough to maintain its impedance at the peak currents expected for the amplifier. Some ferrite bead manufacturers specify the bead impedance at a variety of current levels. In this case it is possible to make sure the ferrite bead maintains an adequate amount of impedance at the peak current the amplifier will see. If these specifications are not available, the device can also estimate the bead current handling capability by measuring the resonant frequency of the filter output at low power and at maximum power. A change of resonant frequency of less than fifty percent under this condition is desirable. Examples of ferrite beads which have been tested and work well with the TPA3136D2 can be seen in the TPA3136D2EVM user guide SLOU444.

A high quality ceramic capacitor is also required for the ferrite bead filter. A low ESR capacitor with good temperature and voltage characteristics will work best.

Additional EMC improvements may be obtained by adding snubber networks from each of the Class-D outputs to ground. Suggested values for a simple RC series snubber network would be 18-Ω in series with a 330-pF capacitor, although design of the snubber network is specific to different applications and must be designed with the consideration of the parasitic reactance of the printed circuit board as well as the audio amp. Take care to evaluate the stress on the component in the snubber network especially if the amp is running at high PVCC. Also, verify the layout of the snubber network is tight and returns directly to the GND pins on the IC.

Figure 29 and Figure 30 are TPA3126D2 EN55022 Radiated Emissions results uses TPA3126D2EVM with 8-Ω speakers.

TPA3126D2 RE_H.gifFigure 29. TPA3126D2 Radiated Emissions-Horizontal (PVCC=19V, PO=1W)
TPA3126D2 RE_V.gifFigure 30. TPA3126D2 Radiated Emissions-Vertical (PVCC=19V, PO=1W)