SLAA701B October   2016  – June 2026 TAS5342A , TAS5342LA , TAS5352 , TAS5630B , TPA3220 , TPA3221 , TPA3251 , TPA3255 , TPA3255-Q1

 

  1.   1
  2.   Trademarks
  3.   Abstract
  4. 1LC Filter Design
    1. 1.1 Class-D Output Configurations
      1. 1.1.1 Bridged-Tied Load (BTL)
      2. 1.1.2 Parallel Bridge-Tied Load (PBTL)
      3. 1.1.3 Single-Ended (SE)
    2. 1.2 Class-D Modulation Schemes
      1. 1.2.1 AD (Traditional) Modulation
      2. 1.2.2 BD Modulation
    3. 1.3 Class-D Output LC Filter
      1. 1.3.1 Output LC Filter Frequency Response Properties
      2. 1.3.2 Class-D BTL Output LC Filter Topologies
      3. 1.3.3 Single-Ended Filter Calculations
      4. 1.3.4 Type-1 Filter Analysis
        1. 1.3.4.1 Type-1 Frequency Response Example
      5. 1.3.5 Type-2 Filter Analysis
        1. 1.3.5.1 Type-2 Frequency Response Example
      6. 1.3.6 Hybrid Filter for AD Modulation
        1. 1.3.6.1 Hybrid Filter Frequency Response Example
      7. 1.3.7 AD Modulation With Type-1 or Type-2 Filters
      8. 1.3.8 LC Filter Quick Selection Guide
    4. 1.4 Inductor Selection for High-Performance Class-D Audio
      1. 1.4.1 Inductor Linearity
      2. 1.4.2 Ripple Current
        1. 1.4.2.1 Calculating Ripple Current for a Single-Supply Class-D Amplifier
      3. 1.4.3 Minimum Inductance
      4. 1.4.4 Core Loss
      5. 1.4.5 DC Resistance (DCR)
      6. 1.4.6 Inductor Study With the TPA3251 Device
        1. 1.4.6.1 Results
        2. 1.4.6.2 Conclusion
    5. 1.5 Capacitor Considerations
      1. 1.5.1 Class-D Output Voltage Overview
        1. 1.5.1.1 Ripple Voltage
        2. 1.5.1.2 37
      2. 1.5.2 Capacitor Ratings and Specifications
        1. 1.5.2.1 Maximum Voltage or Rated DC Voltage
        2. 1.5.2.2 ESR and Dissipation Factor
        3. 1.5.2.3 Maximum Temperature Rise (Rated AC Voltage and AC Current)
        4. 1.5.2.4 Pulse Rise Time (dv/dt) or Peak Current (Ipeak)
      3. 1.5.3 Capacitor Types
        1. 1.5.3.1 Selecting a Capacitor Type
        2. 1.5.3.2 Metalized Film Capacitors
          1. 1.5.3.2.1 AC Voltage or Current Rating
          2. 1.5.3.2.2 Temperature Coefficient
        3. 1.5.3.3 Ceramic Capacitors
          1. 1.5.3.3.1 Size
          2. 1.5.3.3.2 DC Bias Voltage
          3. 1.5.3.3.3 Temperature Coefficient
          4. 1.5.3.3.4 Reliability
    6. 1.6 Related Collateral
  5. 2Reference
  6. 3Reference
  7. 4Revision History

1.5 Capacitor Considerations

Capacitor component selection is critical to maintain flat LC filter frequency response and minimize distortion for the best audio performance. There are a number of capacitor types available including film, ceramic, and electrolytic. This section discusses the key parameters and trade-offs for choosing a capacitor for high-power class-D audio-amplifier applications.

For capacitor recommendations to use with Texas Instruments class-D audio amplifiers, see the device evaluation module (EVM) and EVM user’s guide.