SLOS520A August   2007  – March 2016 TPA2013D1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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  DC Characteristics
    6. 7.6  Boost Converter DC Characteristics
    7. 7.7  Class D Amplifier DC Characteristics
    8. 7.8  AC Characteristics
    9. 7.9  Class D Amplifier AC Characteristics
    10. 7.10 Dissipation Ratings
    11. 7.11 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 Fully Differential Amplifier
        1. 9.3.1.1 Advantages of Fully Differential Amplifiers
      2. 9.3.2 Class-D Amplifier
      3. 9.3.3 Boost Converter
      4. 9.3.4 Operation With DACs and CODECs
      5. 9.3.5 Filter-Free Operation and Ferrite Bead Filters
      6. 9.3.6 Fixed Gain Settings
    4. 9.4 Device Functional Modes
      1. 9.4.1 Boost Converter Mode
      2. 9.4.2 Shutdown Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 TPA2013D1 With Differential Input Signal
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Setting the Boost Voltage
          2. 10.2.1.2.2 Inductor Selection
            1. 10.2.1.2.2.1 Surface Mount Inductors
            2. 10.2.1.2.2.2 TPA2013D1 Inductor Equations
          3. 10.2.1.2.3 Capacitor Selection
            1. 10.2.1.2.3.1 Surface Mount Capacitors
            2. 10.2.1.2.3.2 TPA2013D1 Capacitor Equations
          4. 10.2.1.2.4 Recommended Inductor and Capacitor Values by Application
          5. 10.2.1.2.5 Components Location and Selection
            1. 10.2.1.2.5.1 Decoupling Capacitors
            2. 10.2.1.2.5.2 Input Capacitors
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Bypassing the Boost Converter
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curves
      3. 10.2.3 Stereo Operation Application
        1. 10.2.3.1 Design Requirements
        2. 10.2.3.2 Detailed Design Procedure
        3. 10.2.3.3 Application Curves
      4. 10.2.4 LED Driver for Digital Still Cameras
      5. 10.2.5 Design Requirements
      6. 10.2.6 Detailed Design Procedure
      7. 10.2.7 Application Curves
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Decoupling Capacitors
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Component Placement
        1. 12.1.1.1 Trace Width
      2. 12.1.2 Pad Side
    2. 12.2 Layout Examples
    3. 12.3 Efficiency and Thermal Considerations
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
      2. 13.1.2 Device Nomenclature
        1. 13.1.2.1 Boost Terms
    2. 13.2 Community Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9 Detailed Description

9.1 Overview

The TPA2013D1 is a high efficiency Class D audio power amplifier with an integrated boost converter. It drives up to 2.7 W (10% THD+N) into a 4-Ω speaker. The built-in boost converter generates the voltage rail for the Class-D amplifier. The TPA2013D1 has an integrated low-pass filter to improve RF rejection and reduce out-of-band noise, increasing the signal-to-noise ratio (SNR).

9.2 Functional Block Diagram

TPA2013D1 fbd_los520.gif

9.3 Feature Description

9.3.1 Fully Differential Amplifier

The TPA2013D1 is a fully differential amplifier with differential inputs and outputs. The fully differential amplifier consists of a differential amplifier with common-mode feedback. The differential amplifier ensures that the amplifier outputs a differential voltage on the output that is equal to the differential input times the gain. The common-mode feedback ensures that the common-mode voltage at the output is biased around VCC/2 regardless of the common-mode voltage at the input. The fully differential TPA2013D1 can still be used with a single-ended input; however, the TPA2013D1 must be used with differential inputs when in a noisy environment, like a wireless handset, to ensure maximum noise rejection.

9.3.1.1 Advantages of Fully Differential Amplifiers

  • Input-coupling capacitors not required:
    • The fully differential amplifier allows the inputs to be biased at voltage other than mid-supply. The inputs of the TPA2013D1 can be biased anywhere within the common mode input voltage range listed in the Recommended Operating Conditions. If the inputs are biased outside of that range, input-coupling capacitors are required.
  • Midsupply bypass capacitor, C(BYPASS), not required:
    • The fully differential amplifier does not require a bypass capacitor. Any shift in the midsupply affects both positive and negative channels equally and cancels at the differential output.
  • Better RF-immunity:
    • GSM handsets save power by turning on and shutting off the RF transmitter at a rate of 217 Hz. The transmitted signal is picked-up on input and output traces. The fully differential amplifier cancels the signal better than the typical audio amplifier.

9.3.2 Class-D Amplifier

The TPA2013D1 is a high efficiency Class-D audio power amplifier with an integrated boost converter able to drive up to 2.7 W (10% THD+N) into a 4-Ω speaker with 85% typical efficiency, the device helps extend battery life when playing audio. It is available in 2.275-mm × 2.275-mm 16-ball WCSP and 4-mm × 4-mm 20-lead QFN packages. The device has three selectable gain settings of 2 V/V, 6 V/V and 10 V/V.

9.3.3 Boost Converter

The TPA2013D1 consists of a boost converter and a Class-D amplifier. The boost converter takes a low supply voltage, VDD, and increases it to a higher output voltage, VCC.

The two main passive components necessary for the boost converter are the boost inductor and the boost capacitor. The boost inductor stores current, and the boost capacitor stores charge. As the Class-D amplifier depletes the charge in the boost capacitor, the boost inductor charges it back up with the stored current. The cycle of charge and discharge occurs at a frequency of fboost.

The TPA2013D1 allows a range of VCC voltages, including setting VCC lower than VDD.

9.3.4 Operation With DACs and CODECs

When using switching amplifiers with CODECs and DACs, sometimes there is an increase in the output noise floor from the audio amplifier. This occurs when mixing of the output frequencies of the CODEC and DAC with the switching frequencies of the audio amplifier input stage. The noise increase can be solved by placing a low-pass filter between the CODEC and DAC and audio amplifier. This filters off the high frequencies that cause the problem and allow proper performance.

The TPA2013D1 has a two pole low-pass filter at the inputs. The cutoff frequency of the filter is set to approximately 100 kHz. The integrated low-pass filter of the TPA2013D1 eliminates the need for additional external filtering components. A properly designed additional low-pass filter may be added without altering the performance of the device.

If driving the TPA2013D1 input with 4th-order or higher ΔΣ DACs or CODECs, add an R-C low-pass filter at each of the audio inputs (IN+ and IN–) of the TPA2013D1 to ensure best performance. The recommended resistor value is 100 Ω and the capacitor value of 47 nF.

9.3.5 Filter-Free Operation and Ferrite Bead Filters

A ferrite bead filter can often be used if the design is failing radiated emissions without an LC filter and the frequency sensitive circuit is greater than 1 MHz. This filter functions well for circuits that just have to pass FCC and CE because FCC and CE only test radiated emissions greater than 30 MHz. When choosing a ferrite bead, choose one with high impedance at high frequencies, and very low impedance at low frequencies. In addition, select a ferrite bead with adequate current rating to prevent distortion of the output signal.

Use an LC output filter if there are low-frequency, (< 1 MHz) EMI-sensitive circuits and/or there are long leads from amplifier to speaker.

Figure 32 shows a typical ferrite bead output filters.

TPA2013D1 ferrite_chip_los520.gif Figure 32. Typical Ferrite Chip Bead Filter

Table 1. Suggested Chip Ferrite Bead

LOAD VENDOR PART NUMBER SIZE
8 Ω Murata BLM18EG121SN1 0603
4 Ω TDK MPZ2012S101A 0805

9.3.6 Fixed Gain Settings

The TPA2013D1 has 3 selectable fixed-gains: 6 dB, 15.5 dB, and 20 dB. Connect the GAIN pin as shown in Table 2.

Table 2. Amplifier Fixed-Gain

CONNECT GAIN PIN TO AMPLIFIER GAIN
GND 6 dB
No connection (Floating) 15.5 dB
VBAT 20 dB

9.4 Device Functional Modes

9.4.1 Boost Converter Mode

The TPA2013D1 has 4 boost converter operation modes as shown in Table 3.

Table 3. Boost Converter Mode Condition

CASE OUTPUT CURRENT MODE OF OPERATION
VDD < VCC Low Continuous (fixed frequency)
VDD < VCC High Continuous (fixed frequency)
VDD  ≥ VCC Low Discontinuous (variable frequency)
VDD  ≥ VCC High Discontinuous (variable frequency)

9.4.2 Shutdown Mode

The TPA2013D1 amplifier can be put in shutdown mode when asserting SDd pin to a logic LOW. While in shutdown mode, the device output stage is turned off and the current consumption is very low. The boost converter can be put in shutdown mode when asserting SDb pin to a logic LOW. While in shutdown Mode, the boost converter is turned off.

Table 4. Device Configuration

SDb SDd BOOST CONVERTER CLASS D AMPLIFIER COMMENTS
low low OFF OFF Device is in shutdown mode Iq ≤ 1 μA
low high OFF ON Boost converter is off. Class-D Audio Power Amplifier (APA) can be driven by an external pass transistor connected to the battery.
high low ON OFF Class-D APA is off. Boost Converter is on and can be used to drive an external device.
high high ON ON Boost converter and Class-D APA are on. Normal operation. Boost converter can be used to drive an external device in parallel to the Class-D APA within the limits of the boost converter output current.