SLOS626B December   2009  – November 2015 TPA2011D1

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 Electrical Characteristics
    6. 7.6 Operating Characteristics
    7. 7.7 Dissipation Ratings
    8. 7.8 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 Eliminating the Output Filter With the TPA2011D1
        1. 9.3.2.1 Effect on Audio
        2. 9.3.2.2 When to Use an Output Filter
      3. 9.3.3 Short Circuit Auto-Recovery
      4. 9.3.4 Integrated Image Reject Filter for DAC Noise Rejection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Summing Input Signals With the TPA2011D1
        1. 9.4.1.1 Summing Two Differential Input Signals
        2. 9.4.1.2 Summing a Differential Input Signal and a Single-Ended Input Signal
        3. 9.4.1.3 Summing Two Single-Ended Input Signals
      2. 9.4.2 Shutdown Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 TPA2011D1 with Differential Input
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Input Resistors (RI)
          2. 10.2.1.2.2 Decoupling Capacitor (CS)
        3. 10.2.1.3 Application Curves
      2. 10.2.2 TPA2011D1 with Differential Input and Input Capacitors
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
          1. 10.2.2.2.1 Input Capacitors (CI)
        3. 10.2.2.3 Application Curves
      3. 10.2.3 TPA2011D1 with Single-Ended Input
        1. 10.2.3.1 Design Requirements
        2. 10.2.3.2 Detailed Design Procedure
        3. 10.2.3.3 Application Curves
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Decoupling Capacitors
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Community Resources
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

10 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

10.1 Application Information

These typical connection diagrams highlight the required external components and system level connections for proper operation of the device in several popular use cases. Each of these configurations can be realized using the Evaluation Modules (EVMs) for the device. These flexible modules allow full evaluation of the device in the most common modes of operation. Any design variation can be supported by TI through schematic and layout reviews. Visit e2e.ti.com for design assistance and join the audio amplifier discussion forum for additional information.

10.2 Typical Applications

10.2.1 TPA2011D1 with Differential Input

TPA2011D1 ai_tpa27_slos626.gif Figure 33. Typical TPA2011D1 Application Schematic with Differential Input

10.2.1.1 Design Requirements

For this design example, use the parameters listed in Table 1.

Table 1. Design Parameters

DESIGN PARAMETER EXMAPLE VALUE
Power supply 5 V
Enable input High > 2 V
Low < 0.8 V
Speaker 8 Ω

10.2.1.2 Detailed Design Procedure

10.2.1.2.1 Input Resistors (RI)

The input resistors (RI) set the gain of the amplifier according to the following equation.

Equation 14. TPA2011D1 qu101_slos417.gif

Resistor matching is very important in fully differential amplifiers. The balance of the output on the reference voltage depends on matched ratios of the resistors. CMRR, PSRR, and cancellation of the second harmonic distortion diminish if resistor mismatch occurs. Therefore, it is recommended to use 1% tolerance resistors or better to keep the performance optimized. Matching is more important than overall tolerance. Resistor arrays with 1% matching can be used with a tolerance greater than 1%.

Place the input resistors very close to the TPA2011D1 to limit noise injection on the high-impedance nodes.

For optimal performance, the gain should be set to 2 V/V or lower. Lower gain allows the TPA2011D1 to operate at its best, and keeps a high voltage at the input making the inputs less susceptible to noise.

10.2.1.2.2 Decoupling Capacitor (CS)

The TPA2011D1 is a high-performance class-D audio amplifier that requires adequate power supply decoupling to ensure the efficiency is high and total harmonic distortion (THD) is low. For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series-resistance (ESR) ceramic capacitor, typically 1 μF, placed as close as possible to the device VDD lead works best. Placing this decoupling capacitor close to the TPA2011D1 is very important for the efficiency of the class-D amplifier, because any resistance or inductance in the trace between the device and the capacitor can cause a loss in efficiency. For filtering lower-frequency noise signals, a 10 μF or greater capacitor placed near the audio power amplifier would also help, but it is not required in most applications because of the high PSRR of this device.

10.2.1.3 Application Curves

For application curves, see the figures listed in Table 2.

Table 2. Table of Graphs

DESCRIPTION FIGURE NUMBER
Output Power vs Supply Resistance Figure 11
GSM Power Supply Rejection vs Time Figure 26
GSM Power Supply Rejection vs Frequency Figure 27

10.2.2 TPA2011D1 with Differential Input and Input Capacitors

TPA2011D1 ai_tpa28_slos626.gif Figure 34. TPA2011D1 Application Schematic with Differential Input and Input Capacitors

10.2.2.1 Design Requirements

For this design example, use the parameters listed in Table 1.

10.2.2.2 Detailed Design Procedure

For the design procedure see Input Resistors (RI) and Decoupling Capacitor (CS).

10.2.2.2.1 Input Capacitors (CI)

The TPA2011D1 does not require input coupling capacitors if the design uses a differential source that is biased from 0.5 V to VDD –0.8 V. If the input signal is not biased within the recommended common mode input range, if needing to use the input as a high pass filter, or if using a single-ended source, input coupling capacitors are required.

The input capacitors and input resistors form a high-pass filter with the corner frequency, fC, determined in the following equation.

Equation 15. TPA2011D1 qu102_slos417.gif

The value of the input capacitor is important to consider as it directly affects the bass (low frequency) performance of the circuit. Speakers in wireless phones cannot usually respond well to low frequencies, so the corner frequency can be set to block low frequencies in this application.

The equation below is reconfigured to solve for the input coupling capacitance.

Equation 16. TPA2011D1 qu103_slos417.gif

If the corner frequency is within the audio band, the capacitors should have a tolerance of ±10% or better, because any mismatch in capacitance causes an impedance mismatch at the corner frequency and below.

For a flat low-frequency response, use large input coupling capacitors (1 μF). However, in a GSM phone the ground signal is fluctuating at 217 Hz, but the signal from the codec does not have the same 217 Hz fluctuation. The difference between the two signals is amplified, sent to the speaker, and heard as a 217 Hz hum.

10.2.2.3 Application Curves

For application curves, see the figures listed in Table 2.

10.2.3 TPA2011D1 with Single-Ended Input

TPA2011D1 ai_tpa29_slos626.gif Figure 35. TPA2011D1 Application Schematic with Single-Ended Input

10.2.3.1 Design Requirements

For this design example, use the parameters listed in Table 1.

10.2.3.2 Detailed Design Procedure

For the design procedure see Input Resistors (RI), Decoupling Capacitor (CS), and Input Capacitors (CI).

10.2.3.3 Application Curves

For application curves, see the figures listed in Table 2.