SLOS970B January   2018  – January 2025 TPA6404-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Parameter measurement Information
  8. 7 Detailed description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Differential Analog inputs
      2. 7.3.2 Gain Control and AC-Coupling
      3. 7.3.3 High-Frequency Pulse-Width Modulator (PWM)
      4. 7.3.4 Gate Drive
      5. 7.3.5 Power FETs
      6. 7.3.6 Load Diagnostics
        1. 7.3.6.1 DC Load Diagnostics
          1. 7.3.6.1.1 Automatic DC Load Diagnostics
          2. 7.3.6.1.2 I2C Controlled DC Load Diagnostics
        2. 7.3.6.2 Line Output Diagnostics
        3. 7.3.6.3 AC Load Diagnostics
          1. 7.3.6.3.1 Impedance Phase Reference Measurement
          2. 7.3.6.3.2 Impedance Phase Measurement
          3. 7.3.6.3.3 Impedance Magnitude Measurement
      7. 7.3.7 Protection and Monitoring
        1. 7.3.7.1 Over current Limit (ILIMIT)
        2. 7.3.7.2 Over current Shutdown (ISD)
        3. 7.3.7.3 DC Detect
        4. 7.3.7.4 Clip Detect
        5. 7.3.7.5 Global Over Temperature Warning (OTW), Over Temperature Shutdown (OTSD) and Thermal Foldback (TFB)
        6. 7.3.7.6 Channel Over Temperature Warning [OTW(i)] and Shutdown [OTSD(i)]
        7. 7.3.7.7 Thermal Foldback
        8. 7.3.7.8 Undervoltage (UV) and Power-On-Reset (POR)
        9. 7.3.7.9 Over Voltage (OV) and Load Dump
      8. 7.3.8 Power Supply
        1. 7.3.8.1 Power-Supply Sequence
      9. 7.3.9 Hardware Control Pins
        1. 7.3.9.1 FAULT
        2. 7.3.9.2 WARN
        3. 7.3.9.3 MUTE
        4. 7.3.9.4 STANDBY
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operating Modes and Faults
    5. 7.5 Programming
      1. 7.5.1 I2C Serial Communication Bus
      2. 7.5.2 I2C Bus Protocol
      3. 7.5.3 Random Write
      4. 7.5.4 Sequential Write
      5. 7.5.5 Random Read
      6. 7.5.6 Sequential Read
  9. 8 Registers
    1. 8.1 Register Maps
      1. 8.1.1  Mode Control Register (address = 0x00) [default = 0x00]
      2. 8.1.2  Miscellaneous Control 1 Register (address = 0x01) [default = 0x32]
      3. 8.1.3  Miscellaneous Control 2 Register (address = 0x02) [default = 0x62]
      4. 8.1.4  Channel State Control Register (address = 0x04) [default = 0x55]
      5. 8.1.5  DC Load Diagnostic Control 1 Register (address = 0x09) [default = 0x00]
      6. 8.1.6  DC Load Diagnostic Control 2 Register (address = 0x0A) [default = 0x11]
      7. 8.1.7  DC Load Diagnostic Control 3 Register (address = 0x0B) [default = 0x11]
      8. 8.1.8  DC Load Diagnostic Report 1 Register (address = 0x0C) [default = 0x00]
      9. 8.1.9  DC Load Diagnostic Report 2 Register (address = 0x0D) [default = 0x00]
      10. 8.1.10 DC Load Diagnostics Report 3—Line Output—Register (address = 0x0E) [default = 0x00]
      11. 8.1.11 Channel State Reporting Register (address = 0x0F) [default = 0x55]
      12. 8.1.12 Channel Faults (Over current, DC Detection) Register (address = 0x10) [default = 0x00]
      13. 8.1.13 Global Faults 1 Register (address = 0x11) [default = 0x00]
      14. 8.1.14 Global Faults 2 Register (address = 0x12) [default = 0x00]
      15. 8.1.15 Warnings Register (address = 0x13) [default = 0x20]
      16. 8.1.16 Pin Control Register (address = 0x14) [default = 0x00]
      17. 8.1.17 AC Load Diagnostic Control 1 Register (address = 0x15) [default = 0x00]
      18. 8.1.18 AC Load Diagnostic Control 2 Register (address = 0x16) [default = 0x00]
      19. 8.1.19 AC Load Diagnostic Report Ch1 through CH4 Registers (address = 0x17–0x1A) [default = 0x00]
      20. 8.1.20 AC Load Diagnostic Report Phase High Register (address = 0x1B) [default = 0x00]
      21. 8.1.21 AC Load Diagnostic Report Phase Low Register (address = 0x1C) [default = 0x00]
      22. 8.1.22 AC Load Diagnostic Report STI High Register (address = 0x1D) [default = 0x00]
      23. 8.1.23 AC Load Diagnostic Report STI Low Register (address = 0x1E) [default = 0x00]
      24. 8.1.24 Miscellaneous Control 3 Register (address = 0x21) [default = 0x00]
      25. 8.1.25 Clip Control Register (address = 0x22) [default = 0x01]
      26. 8.1.26 Clip Warning Register (address = 0x24) [default = 0x00]
      27. 8.1.27 Current LIMIT Status Register (address = 0x25) [default = 0x00]
      28. 8.1.28 Fault and Warning Pin Control Register (address = 0x27) [default = 0x7F]
      29. 8.1.29 Thermal Foldback Control Register (address = 0x28) [default = 0x00]
      30. 8.1.30 AC Diagnostic Frequency Control Register (address = 0x2A) [default = 0x32]
      31. 8.1.31 SYNC PIN Control Register (address = 0x2B) [default = 0x02]
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 AM Radio Avoidance
      2. 9.1.2 Parallel BTL Operation (PBTL)
      3. 9.1.3 Reconstruction Filter Design
      4. 9.1.4 Line Driver Applications
    2. 9.2 Typical Applications
      1. 9.2.1 BTL Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Hardware Design
          2. 9.2.1.2.2 Bootstrap Capacitors
          3. 9.2.1.2.3 Output Reconstruction Filter
        3. 9.2.1.3 Application Curves
        4. 9.2.1.4 PBTL Application
          1. 9.2.1.4.1 Design Requirements
          2. 9.2.1.4.2 Detailed Design Procedure
            1. 9.2.1.4.2.1 Hardware Design
          3. 9.2.1.4.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Electrical Connection of Thermal pad and Heat Sink
        2. 9.4.1.2 EMI Considerations
        3. 9.4.1.3 General Considerations
      2. 9.4.2 Layout Example
      3. 9.4.3 Thermal Considerations
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Electrostatic Discharge Caution
    4. 10.4 Glossary
    5. 10.5 Support Resources
    6. 10.6 Trademarks
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Package Option Addendum
      1. 12.1.1 Packaging Information
      2. 12.1.2 Tape and Reel Information

9.4.3 Thermal Considerations

The thermally enhanced PowerPAD package has an exposed pad up for connection to a heat sink. The output power of any amplifier is determined by the thermal performance of the amplifier as well as limitations placed on it by the system such as the ambient operating temperature. The heat sink absorbs heat from the TPA6404-Q1 and transfers it to the air. With proper thermal management this process can reach equilibrium and heat can be continually transferred from the device. Heat sinks can be smaller than that of classic linear amplifier design because of the excellent efficiency of class-D amplifiers. This device is intended for use with a heat sink, therefore, RθJC will be used as the thermal resistance from junction to the exposed metal package. This resistance will dominate the thermal management, so other thermal transfers will not be considered. The thermal resistance of RθJA (junction to ambient) is required to determine the full thermal solution. The thermal resistance is comprised of the following components:

  • RθJC of the TPA6404-Q1
  • Thermal resistance of the thermal interface material
  • Thermal resistance of the heat sink

The thermal resistance of the thermal interface material can be determined from the manufacturer’s value for the area thermal resistance (expressed in °C/mm2W) and the area of the exposed metal package. For example, a typical, white, thermal grease with a 0.0254mm (0.001-inch) thick layer is approximately 4.52°Cmm2/W. The TPA6404-Q1 in the DKQ package has an exposed area of 47.6mm2. By dividing the area thermal resistance by the exposed metal area determines the thermal resistance for the thermal grease. The thermal resistance of the thermal grease is 0.094°C/W

Table 9-1 lists the modeling parameters for one device on a heat sink. The junction temperature is assumed to be 115°C while delivering and average power of 10 watts per channel into a 4Ω load. The thermal-grease example previously described is used for the thermal interface material. Use Equation 1 to design the thermal system.

Equation 1. RθJA = RθJC + thermal interface resistance + heat sink resistance
Table 9-1 Thermal Modeling
DescriptionValue
Ambient Temperature25°C
Average Power to load40W (4x 10w)
Power dissipation8W (4x 2w)
Junction Temperature115°C
ΔT inside package5.6°C (0.7°C/W × 8W)
ΔT through thermal interface material0.75°C (0.094°C/W × 8W)
Required heat sink thermal resistance10.45°C/W ([115°C – 25°C – 5.6°C – 0.75°C] / 8W)
System thermal resistance to ambient RθJA11.24°C/W