SLASEG6C May   2018  – September 2025 TAS3251

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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  Amplifier Electrical Characteristics
    6. 6.6  DAC Electrical Characteristics
    7. 6.7  Audio Characteristics (BTL)
    8. 6.8  Audio Characteristics (PBTL)
    9. 6.9  MCLK Timing
    10. 6.10 Serial Audio Port Timing – Target Mode
    11. 6.11 Serial Audio Port Timing – Controller Mode
    12. 6.12 I2C Bus Timing –Standard
    13. 6.13 I2C Bus Timing –Fast
    14. 6.14 Timing Diagrams
    15. 6.15 Typical Characteristics
      1. 6.15.1 BTL Configuration
      2. 6.15.2 PBTL Configuration
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Power-on-Reset (POR) Function
      2. 7.3.2  Enable Device
      3. 7.3.3  DAC and DSP Clocking
        1. 7.3.3.1 Internal Clock Error Notification (CLKE)
      4. 7.3.4  Serial Audio Port
        1. 7.3.4.1 Clock Controller Mode from Audio Rate Controller Clock
        2. 7.3.4.2 Clock Target Mode with 4-Wire Operation (SCLK, MCLK, LRCK/FS, SDIN)
        3. 7.3.4.3 Clock Target Mode with SCLK PLL to Generate Internal Clocks (3-Wire PCM)
          1. 7.3.4.3.1 Clock Generation Using the PLL
          2. 7.3.4.3.2 PLL Calculation
            1. 7.3.4.3.2.1 Examples:
        4. 7.3.4.4 Serial Audio Port – Data Formats and Bit Depths
          1. 7.3.4.4.1 Data Formats and Controller or Target Modes of Operation
        5. 7.3.4.5 Input Signal Sensing (Power-Save Mode)
      5. 7.3.5  Volume Control
        1. 7.3.5.1 DAC Digital Gain Control
          1. 7.3.5.1.1 Emergency Volume Ramp Down
      6. 7.3.6  SDOUT Port and Hardware Control Pin
      7. 7.3.7  I2C Communication Port
        1. 7.3.7.1 Target Address
        2. 7.3.7.2 Register Address Auto-Increment Mode
        3. 7.3.7.3 Packet Protocol
        4. 7.3.7.4 Write Register
        5. 7.3.7.5 Read Register
        6. 7.3.7.6 DSP Book, Page, and Register Update
          1. 7.3.7.6.1 Book and Page Change
          2. 7.3.7.6.2 Swap Flag
          3. 7.3.7.6.3 Example Use
      8. 7.3.8  Pop and Click Free Startup and Shutdown
      9. 7.3.9  Integrated Oscillator for Output Power Stage
        1. 7.3.9.1 Oscillator Synchronization and Target Mode
      10. 7.3.10 Device Output Stage Protection System
        1. 7.3.10.1 Error Reporting
        2. 7.3.10.2 Overload and Short Circuit Current Protection
        3. 7.3.10.3 Signal Clipping and Pulse Injector
        4. 7.3.10.4 DC Speaker Protection
        5. 7.3.10.5 Pin-to-Pin Short Circuit Protection (PPSC)
        6. 7.3.10.6 Overtemperature Protection OTW and OTE
        7. 7.3.10.7 Undervoltage Protection (UVP) and Power-on Reset (POR)
        8. 7.3.10.8 Fault Handling
        9. 7.3.10.9 Output Power Stage Reset
      11. 7.3.11 Initialization, Startup and Shutdown
        1. 7.3.11.1 Power Up and Startup Sequence
        2. 7.3.11.2 Power Down and Shutdown Sequence
        3. 7.3.11.3 Device Mute
        4. 7.3.11.4 Device Unmute
        5. 7.3.11.5 Device Reset
        6. 7.3.11.6 Mute with DAC_MUTE or Clock Error
          1. 7.3.11.6.1 Mute using DAC_MUTE
        7. 7.3.11.7 Mute using Serial Audio Port Clock
        8. 7.3.11.8 Muting before an Unplanned Shutdown with DAC_MUTE
        9. 7.3.11.9 Output Power Stage Startup Timing
    4. 7.4 Device Functional Modes
      1. 7.4.1 Serial Audio Port Operating Modes
        1. 7.4.1.1 Controller and Target Mode Clocking for Digital Serial Audio Port
      2. 7.4.2 Communication Port Operating Modes
      3. 7.4.3 Speaker Amplifier Operating Modes
        1. 7.4.3.1 Stereo Mode
        2. 7.4.3.2 Mono Mode
    5. 7.5 Programming
      1. 7.5.1 Audio Processing Features
      2. 7.5.2 Processing Block Description
        1. 7.5.2.1  Input Scale and Mixer
          1. 7.5.2.1.1 Example
        2. 7.5.2.2  Sample Rate Converter
        3. 7.5.2.3  Parametric Equalizers (PEQ)
        4. 7.5.2.4  BQ Gain Scale
        5. 7.5.2.5  Dynamic Parametric Equalizer (DPEQ)
        6. 7.5.2.6  Two-Band Dynamic Range Control
        7. 7.5.2.7  Automatic Gain Limiter
          1. 7.5.2.7.1 Softening Filter Alpha (AEA)
          2. 7.5.2.7.2 Softening Filter Omega (AEO)
          3. 7.5.2.7.3 Attack Rate
          4. 7.5.2.7.4 Release Rate
          5. 7.5.2.7.5 Attack Threshold
        8. 7.5.2.8  Fine Volume
        9. 7.5.2.9  THD Boost
        10. 7.5.2.10 Level Meter
      3. 7.5.3 Other Processing Block Features
        1. 7.5.3.1 Number Format
          1. 7.5.3.1.1 Coefficient Format Conversion
      4. 7.5.4 Checksum
        1. 7.5.4.1 Cyclic Redundancy Check (CRC) Checksum
        2. 7.5.4.2 Exclusive or (XOR) Checksum
    6. 7.6 Register Maps
      1. 7.6.1 Registers - Page 0
        1. 7.6.1.1  Register 1 (0x01)
        2. 7.6.1.2  Register 2 (0x02)
        3. 7.6.1.3  Register 3 (0x03)
        4. 7.6.1.4  Register 4 (0x04)
        5. 7.6.1.5  Register 6 (0x06)
        6. 7.6.1.6  Register 7 (0x07)
        7. 7.6.1.7  Register 8 (0x08)
        8. 7.6.1.8  Register 9 (0x09)
        9. 7.6.1.9  Register 12 (0x0C)
        10. 7.6.1.10 Register 13 (0x0D)
        11. 7.6.1.11 Register 14 (0x0E)
        12. 7.6.1.12 Register 15 (0x0F)
        13. 7.6.1.13 Register 16 (0x10)
        14. 7.6.1.14 Register 17 (0x11)
        15. 7.6.1.15 Register 18 (0x12)
        16. 7.6.1.16 Register 20 (0x14)
        17. 7.6.1.17 Register 21 (0x15)
        18. 7.6.1.18 Register 22 (0x16)
        19. 7.6.1.19 Register 23 (0x17)
        20. 7.6.1.20 Register 24 (0x18)
        21. 7.6.1.21 Register 27 (0x1B)
        22. 7.6.1.22 Register 28 (0x1C)
        23. 7.6.1.23 Register 29 (0x1D)
        24. 7.6.1.24 Register 30 (0x1E)
        25. 7.6.1.25 Register 32 (0x20)
        26. 7.6.1.26 Register 33 (0x21)
        27. 7.6.1.27 Register 34 (0x22)
        28. 7.6.1.28 Register 37 (0x25)
        29. 7.6.1.29 Register 40 (0x28)
        30. 7.6.1.30 Register 41 (0x29)
        31. 7.6.1.31 Register 42 (0x2A)
        32. 7.6.1.32 Register 43 (0x2B)
        33. 7.6.1.33 Register 44 (0x2C)
        34. 7.6.1.34 Register 59 (0x3B)
        35. 7.6.1.35 Register 60 (0x3C)
        36. 7.6.1.36 Register 61 (0x3D)
        37. 7.6.1.37 Register 62 (0x3E)
        38. 7.6.1.38 Register 63 (0x3F)
        39. 7.6.1.39 Register 64 (0x40)
        40. 7.6.1.40 Register 65 (0x41)
        41. 7.6.1.41 Register 67 (0x43)
        42. 7.6.1.42 Register 68 (0x44)
        43. 7.6.1.43 Register 69 (0x45)
        44. 7.6.1.44 Register 70 (0x46)
        45. 7.6.1.45 Register 71 (0x47)
        46. 7.6.1.46 Register 72 (0x48)
        47. 7.6.1.47 Register 73 (0x49)
        48. 7.6.1.48 Register 74 (0x4A)
        49. 7.6.1.49 Register 75 (0x4B)
        50. 7.6.1.50 Register 76 (0x4C)
        51. 7.6.1.51 Register 78 (0x4E)
        52. 7.6.1.52 Register 79 (0x4F)
        53. 7.6.1.53 Register 85 (0x55)
        54. 7.6.1.54 Register 86 (0x56)
        55. 7.6.1.55 Register 87 (0x57)
        56. 7.6.1.56 Register 88 (0x58)
        57. 7.6.1.57 Register 91 (0x5B)
        58. 7.6.1.58 Register 92 (0x5C)
        59. 7.6.1.59 Register 93 (0x5D)
        60. 7.6.1.60 Register 94 (0x5E)
        61. 7.6.1.61 Register 95 (0x5F)
        62. 7.6.1.62 Register 108 (0x6C)
        63. 7.6.1.63 Register 119 (0x77)
        64. 7.6.1.64 Register 120 (0x78)
      2. 7.6.2 Registers - Page 1
        1. 7.6.2.1 Register 1 (0x01)
        2. 7.6.2.2 Register 2 (0x02)
        3. 7.6.2.3 Register 6 (0x06)
        4. 7.6.2.4 Register 7 (0x07)
        5. 7.6.2.5 Register 9 (0x09)
  9. 8 Application and Implementation
    1. 8.1 Typical Applications
      1. 8.1.1 Stereo, Bridge Tied Load (BTL) Application
      2. 8.1.2 Mono, Parallel Bridge-Tied Load (PBTL) Application
        1. 8.1.2.1 Parallel Bridge-Tied Load (PBTL), Pre-Filter
        2. 8.1.2.2 Parallel Bridge-Tied Load, Post-Filter
      3. 8.1.3 Design Requirements
      4. 8.1.4 Detailed Design Procedure
        1. 8.1.4.1 Step One: Schematic and Layout Design
          1. 8.1.4.1.1 Decoupling Capacitor Recommendations
          2. 8.1.4.1.2 PVDD Capacitor Recommendations
          3. 8.1.4.1.3 BST Capacitors
          4. 8.1.4.1.4 Heatsink
        2. 8.1.4.2 Step Two: Configure the Fixed-Function Process Flow for Use with the Target System
        3. 8.1.4.3 Step Three: Software Integration
      5. 8.1.5 Two TAS3251 Device Configurations
        1. 8.1.5.1 2 x PBTL Application
        2. 8.1.5.2 2 x BTL + 1 x PBTL Application
      6. 8.1.6 Three or More TAS3251 Device Configurations
      7. 8.1.7 Application Curves
    2. 8.2 Power Supply Recommendations
      1. 8.2.1 Power Supplies
        1. 8.2.1.1 DAC_DVDD and DAC_AVDD Supplies
          1. 8.2.1.1.1 CPVSS, CN and CP Charge Pump
        2. 8.2.1.2 VDD Supply
        3. 8.2.1.3 GVDD_X Supply
        4. 8.2.1.4 PVDD Supply
        5. 8.2.1.5 BST Supply
    3. 8.3 Layout
      1. 8.3.1 Layout Guidelines
        1. 8.3.1.1 General Guidelines for TAS3251
        2. 8.3.1.2 Importance of PVDD Bypass Capacitor Placement
      2. 8.3.2 Layout Examples
        1. 8.3.2.1 Bridge-Tied Load (BTL) Layout Example
        2. 8.3.2.2 Parallel Bridge-Tied Load (PBTL), Pre-Filter
        3. 8.3.2.3 Parallel Bridge-Tied Load (PBTL), Post-Filter
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Device Nomenclature
      2. 9.1.2 Development Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.3.3 DAC and DSP Clocking

The TAS3251 front-end (DAC and DSP) has flexible systems for clocking. Internally, the device requires a number of clocks, mostly at related clock rates to function correctly. All of these clocks can be derived from the Serial Audio Interface in one form or another. See section Oscillator for Output Power Stagefor setting the output stage oscillator and switching frequency.

TAS3251 Audio Flow with Respective ClocksFigure 7-1 Audio Flow with Respective Clocks

Figure 7-1 shows the basic data flow at basic sample rate (fS). When the data is brought into the serial audio interface, the data is processed, interpolated and modulated to 128 × fS before arriving at the current segments for the final digital to analog conversion.

Figure 7-2 shows the clock tree.

TAS3251 TAS3251 Clock Distribution Tree Figure 7-2 TAS3251 Clock Distribution Tree

The Serial Audio Interface typically has 4 connection pins which are listed as follows:

  • MCLK (System Controller Clock)
  • SCLK (Serial or Bit Clock)
  • LRCK/FS (Left-Right Word Clock and Frame Sync)
  • SDIN (Input Data)
  • SDOUT can be used to output pre- or post-processed DSP data for use externally (See the SDOUT Port and Hardware Control Pins section)

The device has an internal PLL that is used to take either MCLK or SCLK and create the higher rate clocks required by the DSP and the DAC clock.

In situations where the highest audio performance is required, bringing MCLK to the device along with SCLK and LRCK/FS is recommended. The device should be configured so that the PLL is only providing a clock source to the DSP. All other clocks are then a division of the incoming MCLK. To enable the MCLK as the main source clock, with all others being created as divisions of the incoming MCLK, set the DAC CLK source mux (SDAC in Figure 7-2) to use MCLK as a source, rather than the output of the MCLK/PLL mux.