SLOS989B November   2017  – November 2019 TAS5720A-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Functional Block Diagram
  4. 4 Revision History
  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  Digital I/O Pins
    6. 6.6  Master Clock
    7. 6.7  Serial Audio Port
    8. 6.8  Protection Circuitry
    9. 6.9  Speaker Amplifier in All Modes
    10. 6.10 Speaker Amplifier in All Modes
    11. 6.11 I²C Control Port
    12. 6.12 Typical Idle, Mute, Shutdown, Operational Power Consumption
    13. 6.13 Typical Characteristics (Mono Mode): fSPK_AMP = 384 kHz
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
      1. 8.2.1 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Power Supplies
      2. 8.3.2 Speaker Amplifier Audio Signal Path
        1. 8.3.2.1 Serial Audio Port (SAP)
          1. 8.3.2.1.1 I²S Timing
          2. 8.3.2.1.2 Left-Justified
          3. 8.3.2.1.3 Right-Justified
        2. 8.3.2.2 DC Blocking Filter
        3. 8.3.2.3 Digital Boost and Volume Control
        4. 8.3.2.4 Digital Clipper
        5. 8.3.2.5 Closed-Loop Class-D Amplifier
      3. 8.3.3 Speaker Amplifier Protection Suite
        1. 8.3.3.1 Speaker Amplifier Fault Notification (SPK_FAULT Pin)
        2. 8.3.3.2 DC Detect Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Hardware Control Mode
        1. 8.4.1.1 Speaker Amplifier Shut Down (SPK_SD Pin)
        2. 8.4.1.2 Serial Audio Port in Hardware Control Mode
        3. 8.4.1.3 Soft Clipper Control (SFT_CLIP Pin)
        4. 8.4.1.4 Speaker Amplifier Switching Frequency Select (FREQ/SDA Pin)
        5. 8.4.1.5 Hardware Control Mode Select (HW/SCL Pin)
        6. 8.4.1.6 Speaker Amplifier Sleep Enable (SPK_SLEEP/ADR Pin)
        7. 8.4.1.7 Speaker Amplifier Gain Select (SPK_GAIN [1:0] Pins)
        8. 8.4.1.8 Considerations for Setting the Speaker Amplifier Gain Structure
          1. 8.4.1.8.1 Recommendations for Setting the Speaker Amplifier Gain Structure in Hardware Control Mode
      2. 8.4.2 Software Control Mode
        1. 8.4.2.1 Speaker Amplifier Shut Down (SPK_SD Pin)
        2. 8.4.2.2 Serial Audio Port Controls
          1. 8.4.2.2.1 Serial Audio Port (SAP) Clocking
        3. 8.4.2.3 Channel Select via Software Control
        4. 8.4.2.4 Speaker Amplifier Gain Structure
          1. 8.4.2.4.1 Speaker Amplifier Gain in Software Control Mode
        5. 8.4.2.5 I²C Software Control Port
          1. 8.4.2.5.1 Setting the I²C Device Address
          2. 8.4.2.5.2 General Operation of the I²C Control Port
          3. 8.4.2.5.3 Writing to the I²C Control Port
          4. 8.4.2.5.4 Reading from the I²C Control Port
    5. 8.5 Register Maps
      1. 8.5.1 Control Port Registers - Quick Reference
      2. 8.5.2 Control Port Registers - Detailed Description
        1. 8.5.2.1  Device Identification Register (0x00)
          1. Table 9. Device Identification Register Field Descriptions
        2. 8.5.2.2  Power Control Register (0x01)
          1. Table 10. Power Control Register Field Descriptions
        3. 8.5.2.3  Digital Control Register (0x02)
          1. Table 11. Digital Control Register Field Descriptions
        4. 8.5.2.4  Volume Control Configuration Register (0x03)
          1. Table 12. Volume Control Configuration Register Field Descriptions
        5. 8.5.2.5  Left Channel Volume Control Register (0x04)
          1. Table 13. Left Channel Volume Control Register Field Descriptions
        6. 8.5.2.6  Right Channel Volume Control Register (0x05)
          1. Table 14. Right Channel Volume Control Register Field Descriptions
        7. 8.5.2.7  Analog Control Register (0x06)
          1. Table 15. Analog Control Register Field Descriptions
        8. 8.5.2.8  Reserved Register (0x07)
        9. 8.5.2.9  Fault Configuration and Error Status Register (0x08)
          1. Table 16. Fault Configuration and Error Status Register Field Descriptions
        10. 8.5.2.10 Reserved Controls (9 / 0x09) - (15 / 0x0F)
        11. 8.5.2.11 Digital Clipper Control 2 Register (0x10)
          1. Table 17. Digital Clipper Control 2 Register Field Descriptions
        12. 8.5.2.12 Digital Clipper Control 1 Register (0x11)
          1. Table 18. Digital Clipper Control 1 Register Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Mono Output Using Software Control
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Startup Procedures- Software Control Mode
          2. 9.2.1.2.2 Shutdown Procedures- Software Control Mode
          3. 9.2.1.2.3 Component Selection and Hardware Connections
            1. 9.2.1.2.3.1 I²C Pull-Up Resistors
            2. 9.2.1.2.3.2 Digital I/O Connectivity
      2. 9.2.2 Mono Output Using Hardware Control
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Startup Procedures- Hardware Control Mode
          2. 9.2.2.2.2 Shutdown Procedures- Hardware Control Mode
          3. 9.2.2.2.3 Digital I/O Connectivity
        3. 9.2.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 DVDD Supply
    2. 10.2 PVDD Supply
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 General Guidelines for Audio Amplifiers
      2. 11.1.2 Importance of PVDD Bypass Capacitor Placement on PVDD Network
      3. 11.1.3 Optimizing Thermal Performance
        1. 11.1.3.1 Device, Copper, and Component Layout
        2. 11.1.3.2 Stencil Pattern
          1. 11.1.3.2.1 PCB Footprint and Via Arrangement
            1. 11.1.3.2.1.1 Solder Stencil
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.4.1.3 Soft Clipper Control (SFT_CLIP Pin)

The TAS5720A-Q1 has a soft clipper that can be used to clip the output voltage level below the supply rail. When this circuit is active, the amplifier operates as if it was powered by a lower supply voltage, and thereby enters into clipping sooner than if the circuit was not active. The result is clipping behavior very similar to that of clipping at the PVDD rail, in contrast to the digital clipper behavior which occurs in the oversampled domain of the digital path. The point at which clipping begins is controlled by a resistor divider from GVDD_REG to ground, which sets the voltage at the SFT_CLIP pin. The precision of the threshold at which clipping occurs is dependent upon the voltage level at the SFT_CLIP pin. Because of this, increasing the precision of the resistors used to create the voltage divider, or using an external reference will increase the precision of the point at which the device enters into clipping. To ensure stability, and soften the edges of the clipping event, a capacitor should be connected from pin SFT_CLIP to ground.

TAS5720A-Q1 POWER_LIMIT_example_los708.gifFigure 8. Soft Clipper Example Wave Form

To move the output stage into clipping, the soft clipper circuit limits the duty cycle of the output PWM pulses to a fixed maximum value. After filtering this limit applied to the duty cycle resembles a clipping event at a voltage below that of the PVDD level. The peak voltage level attainable when the soft clipper circuit is active, called VP in the example below, is approximately 4 times the voltage at the SFT_CLIP pin, noted as VSFT_CLIP. This voltage can be used to calculate the maximum output power for a given maximum input voltage and speaker impedance, as shown in the equation below.

Equation 2. TAS5720A-Q1 EQ1_Pout_los708.gif

Where:

RS is the total series resistance including RDS(on), and output filter resistance.
RL is the load resistance.
VP is the peak amplitude achievable when the soft clipper circuit is active (As mentioned previously, VP = [4 x VSFT_CLIP], provided that [4 x VSFT_CLIP] < PVDD.)
POUT (10%THD) ≈ 1.25 × POUT (unclipped)

If the PVDD level is below (4 x VSFT_CLIP) clipping will occur due to clipping at PVDD before the clipping due to the soft clipper circuit becomes active.

Table 4. Soft Clipper Example

PVDD [V] SFT_CLIP Pin Voltage [V](1) Resistor to GND [kΩ] Resistor to GVDD [kΩ] Output Voltage [Vrms]
24 GVDD (Open) 0 17.90
24 3.3 45 51 12.67
24 2.25 24 51 9.00
12 GVDD (Open) 0 10.33
12 2.25 24 51 9.00
12 1.5 18 68 6.30
(1) Output voltage measurements are dependent upon gain settings.