SLOS704B January  2011  – August 2015 TPA6138A2

PRODUCTION DATA. 

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1Absolute Maximum Ratings
    2. 7.2ESD Ratings
    3. 7.3Recommended Operating Conditions
    4. 7.4Thermal Information
    5. 7.5Electrical Characteristics
    6. 7.6Operating Characteristics
    7. 7.7Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1Overview
    2. 9.2Functional Block Diagram
    3. 9.3Feature Description
      1. 9.3.1Direct Path Headphone Driver
    4. 9.4Device Functional Modes
      1. 9.4.1Mute Operation
      2. 9.4.2Using the TPA6138A2 as a Second-Order Filter
      3. 9.4.3TPA6138A2 UVP Operation
  10. 10Application and Implementation
    1. 10.1Application Information
      1. 10.1.1Gain-Setting Resistor Ranges
      2. 10.1.2Input-Blocking Capacitors
    2. 10.2Typical Application
      1. 10.2.1Design Requirements
      2. 10.2.2Detailed Design Procedure
        1. 10.2.2.1Charge-Pump Flying Capacitor and VSS Capacitor
        2. 10.2.2.2Decoupling Capacitors
      3. 10.2.3Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1Layout Guidelines
      1. 12.1.1Gain-Setting Resistors
      2. 12.1.2Decoupling Capacitors Placement
    2. 12.2Layout Example
  13. 13Device and Documentation Support
    1. 13.1Device Support
      1. 13.1.1Development Support
    2. 13.2Community Resources
    3. 13.3Trademarks
    4. 13.4Electrostatic Discharge Caution
    5. 13.5Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information

1 Features

  • Stereo DirectPath™ Headphone Amplifier
    • 40 mW Into 32 Ω With 3.3-V Supply
  • Low THD+N < 0.01% at 10 mW Into 32 Ω
  • High SNR, >90 dB
  • Differential Input and Single-Ended Output
  • Adjustable Gain by External Gain-Setting Resistors
  • Configurable as a Second-Order Low-Pass Filter
    • Ideal for PWM Audio Sources
  • Low DC Offset, <1 mV
  • Ground-Referenced Outputs Eliminate DC-Blocking Capacitors
    • Reduce Board Area
    • Reduce Component Cost
    • Improve THD+N Performance
    • No Degradation of Low-Frequency Response Due to Output Capacitors
  • Short-Circuit Protection
  • Click- and Pop-Reduction Circuitry
  • External Undervoltage Mute
  • Active Mute Control for Pop-Free Audio On/Off Control
  • Space-Saving TSSOP Package

2 Applications

  • LCD and PDP TV
  • Blu-ray Disc™, DVD Players
  • Set-Top Boxes
  • Mini/Micro Combo Systems
  • Sound Cards
  • Laptops

3 Description

The TPA6138A2 is a pop-free stereo headphone amplifier designed to allow the removal of the output dc-blocking capacitors for reduced component count and cost. The device is ideal for single-supply electronics where size and cost are critical design parameters.

Designed using TI’s patented DirectPath™ technology, The TPA6138A2 is capable of driving 25 mW into a 32-Ω load with 3.3-V supply voltage. The device has differential inputs and uses external gain-setting resistors that supports a gain range of ±1 V/V to ±10 V/V. Gain can be configured individually for each channel. The device can also be configured as a second-order low-pass filter and is ideal for interfacing with PWM audio sources. Audio output compiles with ±8-kV IEC ESD protection, requiring just a simple resistor-capacitor ESD protection circuit. The TPA6138A2 has built-in active-mute control for pop-free audio on/off control. The TPA6138A2 has an external undervoltage detector that mutes the output when the power supply is removed, ensuring a pop-free shutdown.

Using the TPA6138A2 in audio products can reduce component count considerably compared to traditional headphone amplifiers. The TPA6138A2 does not require a split-rail power supply or a dc blocking capacitor. The TPA6138A2 integrates its own charge pump to generate a negative supply rail that provides a clean, pop-free ground-biased audio signal.

The TPA6138A2 is available in a 14-pin TSSOP.

Device Information(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
TPA6138A2TSSOP (14)5.00 mm × 4.40 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Diagram

TPA6138A2 block_diagram_slos704.gif