JAJSCV9C May   2016  – January 2018 TPA3128D2 , TPA3129D2

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      アプリケーションの簡略回路図
  4. 4 改訂履歴
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 DC Electrical Characteristics
    6. 6.6 AC Electrical Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Gain Setting and Master and Slave
      2. 7.3.2  Input Impedance
      3. 7.3.3  Startup and Shutdown Operation
      4. 7.3.4  PLIMIT Operation
      5. 7.3.5  GVDD Supply
      6. 7.3.6  BSPx AND BSNx Capacitors
      7. 7.3.7  Differential Inputs
      8. 7.3.8  Device Protection System
      9. 7.3.9  DC Detect Protection
      10. 7.3.10 Short-Circuit Protection and Automatic Recovery Feature
      11. 7.3.11 Thermal Protection
      12. 7.3.12 Device Modulation Scheme
        1. 7.3.12.1 BD-Modulation
      13. 7.3.13 Efficiency: LC Filter Required with the Traditional Class-D Modulation Scheme
      14. 7.3.14 Ferrite Bead Filter Considerations
      15. 7.3.15 When to Use an Output Filter for EMI Suppression
      16. 7.3.16 AM Avoidance EMI Reduction
    4. 7.4 Device Functional Modes
      1. 7.4.1 PBTL Mode
      2. 7.4.2 Mono Mode (Single Channel Mode)
  8. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requriements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Select the PWM Frequency
        2. 8.2.2.2 Select the Amplifier Gain and Master/Slave Mode
        3. 8.2.2.3 Select Input Capacitance
        4. 8.2.2.4 Select Decoupling Capacitors
        5. 8.2.2.5 Select Bootstrap Capacitors
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 Power Supply Mode
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 ドキュメントのサポート
    2. 11.2 コミュニティ・リソース
    3. 11.3 商標
    4. 11.4 静電気放電に関する注意事項
    5. 11.5 Glossary
  12. 12メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

7.3.2 Input Impedance

The TPA31xxD2 input stage is a fully differential input stage and the input impedance changes with the gain setting from 9 kΩ at 36 dB gain to 60 kΩ at 20 dB gain. Table 1 lists the values from min to max gain. The tolerance of the input resistor value is ±20% so the minimum value will be higher than 7.2 kΩ. The inputs must be AC-coupled to minimize the output dc-offset and ensure correct ramping of the output voltages during power-ON and power-OFF. The input ac-coupling capacitor together with the input impedance forms a high-pass filter with the following cut-off frequency:

Equation 1. TPA3128D2 TPA3129D2 EQ2_los708.gif

If a flat bass response is required down to 20 Hz the recommended cut-off frequency is a tenth of that, 2 Hz. Table 2 lists the recommended ac-couplings capacitors for each gain step. If a –3-dB capacitor is accepted at 20 Hz 10 times lower capacitors can used – for example, a 1-µF capacitor can be used.

Table 2. Recommended Input AC-Coupling Capacitors

GAININPUT IMPEDANCEINPUT CAPACITANCEHIGH-PASS FILTER
20 dB 60 kΩ 1.5 µF 1.8 Hz
26 dB 30 kΩ 3.3 µF 1.6 Hz
32 dB 15 kΩ 5.6 µF 2.3 Hz
36 dB 9 kΩ 10 µF 1.8 Hz
TPA3128D2 TPA3129D2 INPUT_IMPEDANCE_los708.gifFigure 26. Input Impedance

The input capacitors used should be a type with low leakage, such as quality electrolytic, tantalum, or ceramic capacitors. If a polarized type is used the positive connection should face the input pins which are biased to 3 Vdc.