SLOSE32A April   2019  – October 2019 TAS6421-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Functional Block Diagram
  4. 4 Revision History
  5. 5 Device Options
  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 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  Serial Audio Port
        1. 9.3.1.1 I2S Mode
        2. 9.3.1.2 Left-Justified Timing
        3. 9.3.1.3 Right-Justified Timing
        4. 9.3.1.4 TDM Mode
        5. 9.3.1.5 Supported Clock Rates
        6. 9.3.1.6 Audio-Clock Error Handling
      2. 9.3.2  DC Blocking
      3. 9.3.3  Volume Control and Gain
      4. 9.3.4  High-Frequency Pulse-Width Modulator (PWM)
      5. 9.3.5  Gate Drive
      6. 9.3.6  Power FETs
      7. 9.3.7  Load Diagnostics
        1. 9.3.7.1 DC Load Diagnostics
        2. 9.3.7.2 Line Output Diagnostics
        3. 9.3.7.3 AC Load Diagnostics
          1. 9.3.7.3.1 Impedance Magnitude Measurement
          2. 9.3.7.3.2 Impedance Phase Reference Measurement
          3. 9.3.7.3.3 Impedance Phase Measurement
      8. 9.3.8  Protection and Monitoring
        1. 9.3.8.1 Overcurrent Limit (ILIMIT)
        2. 9.3.8.2 Overcurrent Shutdown (ISD)
        3. 9.3.8.3 DC Detect
        4. 9.3.8.4 Clip Detect
        5. 9.3.8.5 Global Overtemperature Warning (OTW), Overtemperature Shutdown (OTSD)
        6. 9.3.8.6 Channel Overtemperature Warning [OTW(i)] and Shutdown [OTSD(i)]
        7. 9.3.8.7 Undervoltage (UV) and Power-On-Reset (POR)
        8. 9.3.8.8 Overvoltage (OV) and Load Dump
      9. 9.3.9  Power Supply
        1. 9.3.9.1 Vehicle-Battery Power-Supply Sequence
          1. 9.3.9.1.1 Power-Up Sequence
          2. 9.3.9.1.2 Power-Down Sequence
        2. 9.3.9.2 Boosted Power-Supply Sequence
      10. 9.3.10 Hardware Control Pins
        1. 9.3.10.1 FAULT
        2. 9.3.10.2 WARN
        3. 9.3.10.3 MUTE
        4. 9.3.10.4 STANDBY
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operating Modes and Faults
    5. 9.5 Programming
      1. 9.5.1 I2C Serial Communication Bus
      2. 9.5.2 I2C Bus Protocol
      3. 9.5.3 Random Write
      4. 9.5.4 Sequential Write
      5. 9.5.5 Random Read
      6. 9.5.6 Sequential Read
    6. 9.6 Register Maps
      1. 9.6.1  Mode Control Register (address = 0x00) [default = 0x00]
        1. Table 9. Mode Control Field Descriptions
      2. 9.6.2  Miscellaneous Control 1 Register (address = 0x01) [default = 0x32]
        1. Table 10. Misc Control 1 Field Descriptions
      3. 9.6.3  Miscellaneous Control 2 Register (address = 0x02) [default = 0x62]
        1. Table 11. Misc Control 2 Field Descriptions
      4. 9.6.4  SAP Control (Serial Audio-Port Control) Register (address = 0x03) [default = 0x04]
        1. Table 12. SAP Control Field Descriptions
      5. 9.6.5  Channel State Control Register (address = 0x04) [default = 0x55]
        1. Table 13. Channel State Control Field Descriptions
      6. 9.6.6  Channel 1 Volume Control Register (address = 0x05) [default = 0xCF]
        1. Table 14. Ch 1 Volume Control Field Descriptions
      7. 9.6.7  DC Load Diagnostic Control 1 Register (address = 0x09) [default = 0x00]
        1. Table 15. DC Load Diagnostics Control 1 Field Descriptions
      8. 9.6.8  DC Load Diagnostic Control 2 Register (address = 0x0A) [default = 0x11]
        1. Table 16. DC Load Diagnostics Control 2 Field Descriptions
      9. 9.6.9  DC Load Diagnostic Report 1 Register (address = 0x0C) [default = 0x00]
        1. Table 17. DC Load Diagnostics Report 1 Field Descriptions
      10. 9.6.10 DC Load Diagnostics Report 3 Line Output Register (address = 0x0E) [default = 0x00]
        1. Table 18. DC Load Diagnostics Report 3 Line Output Field Descriptions
      11. 9.6.11 Channel State Reporting Register (address = 0x0F) [default = 0x40]
        1. Table 19. State-Reporting Field Descriptions
      12. 9.6.12 Channel Faults (Overcurrent, DC Detection) Register (address = 0x10) [default = 0x00]
        1. Table 20. Channel Faults Field Descriptions
      13. 9.6.13 Global Faults 1 Register (address = 0x11) [default = 0x00]
        1. Table 21. Global Faults 1 Field Descriptions
      14. 9.6.14 Global Faults 2 Register (address = 0x12) [default = 0x00]
        1. Table 22. Global Faults 2 Field Descriptions
      15. 9.6.15 Warnings Register (address = 0x13) [default = 0x20]
        1. Table 23. Warnings Field Descriptions
      16. 9.6.16 Pin Control Register (address = 0x14) [default = 0x00]
        1. Table 24. Pin Control Field Descriptions
      17. 9.6.17 AC Load Diagnostic Control 1 Register (address = 0x15) [default = 0x00]
        1. Table 25. AC Load Diagnostic Control 1 Field Descriptions
      18. 9.6.18 AC Load Diagnostic Control 2 Register (address = 0x16) [default = 0x00]
        1. Table 26. AC Load Diagnostic Control 2 Field Descriptions
      19. 9.6.19 AC Load Diagnostic Impedance Report Ch1 Register (address = 0x17) [default = 0x00]
        1. Table 27. Ch1 AC LDG Impedance Report Field Descriptions
      20. 9.6.20 AC Load Diagnostic Phase Report High Register (address = 0x1B) [default = 0x00]
        1. Table 28. AC LDG Phase High Report Field Descriptions
      21. 9.6.21 AC Load Diagnostic Phase Report Low Register (address = 0x1C) [default = 0x00]
        1. Table 29. AC LDG Phase Low Report Field Descriptions
      22. 9.6.22 AC Load Diagnostic STI Report High Register (address = 0x1D) [default = 0x00]
        1. Table 30. AC LDG STI High Report Field Descriptions
      23. 9.6.23 AC Load Diagnostic STI Report Low Register (address = 0x1E) [default = 0x00]
        1. Table 31. Ch1 AC LDG STI Low Report Field Descriptions
      24. 9.6.24 Miscellaneous Control 3 Register (address = 0x21) [default = 0x00]
        1. Table 32. Misc Control 3 Field Descriptions
      25. 9.6.25 Clip Control Register (address = 0x22) [default = 0x01]
        1. Table 33. Clip Control Field Descriptions
      26. 9.6.26 Clip Window Register (address = 0x23) [default = 0x14]
        1. Table 34. Clip Window Field Descriptions
      27. 9.6.27 Clip Warning Register (address = 0x24) [default = 0x00]
        1. Table 35. Clip Warning Field Descriptions
      28. 9.6.28 ILIMIT Status Register (address = 0x25) [default = 0x00]
        1. Table 36. ILIMIT Status Field Descriptions
      29. 9.6.29 Miscellaneous Control 4 Register (address = 0x26) [default = 0x40]
        1. Table 37. Misc Control 4 Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 AM-Radio Band Avoidance
      2. 10.1.2 Demodulation Filter Design
      3. 10.1.3 Line Driver Applications
    2. 10.2 Typical Applications
      1. 10.2.1 BTL Application
        1. 10.2.1.1 Design Requirements
          1. 10.2.1.1.1 Communication
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Hardware Design
          2. 10.2.1.2.2 Digital Input and the Serial Audio Port
          3. 10.2.1.2.3 Bootstrap Capacitors
          4. 10.2.1.2.4 Output Reconstruction Filter
      2. 10.2.2 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Electrical Connection of Thermal pad and Heat Sink
      2. 12.1.2 EMI Considerations
      3. 12.1.3 General Guidelines
    2. 12.2 Layout Example
    3. 12.3 Thermal Considerations
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary

Package Options

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

12.3 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 TAS6421-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 is used as the thermal resistance from junction to the exposed metal package. This resistance dominates the thermal management, so other thermal transfers are not 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 TAS6421-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 °Cmm2/W) and the area of the exposed metal package. For example, a typical, white, thermal grease with a 0.0254 mm (0.001 inch) thick layer is approximately 4.52°C mm2/W. The TAS6421-Q1 in the DKQ package has an exposed area of 47.6 mm2. 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 38 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 4 Ω load. The thermal-grease example previously described is used for the thermal interface material. Use Equation 3 to design the thermal system.

Equation 3. RθJA = RθJC + thermal interface resistance + heat sink resistance

Table 38. Thermal Modeling

Description Value
Ambient Temperature 25°C
Average Power to load 10W
Power dissipation 2W
Junction Temperature 115°C
ΔT inside package 1.8°C (0.9°C/W × 2W)
ΔT through thermal interface material 0.188°C (0.094°C/W × 2W)
Required heat sink thermal resistance 44.0°C/W ([115°C – 25°C – 1.8°C – 0.188°C] / 2W)
System thermal resistance to ambient RθJA 45.1°C/W