SLOS369G July   2002  – October 2015 TPA2005D1


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  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 Typical Characteristics
  8. Parameter Measurement Information
  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. Advantages of Fully Differential Amplifiers
      2. 9.3.2 Efficiency and Thermal Information
      3. 9.3.3 Eliminating the Output Filter with the TPA2005D1
        1. Effect on Audio
        2. Traditional Class-D Modulation Scheme
        3. TPA2005D1 Modulation Scheme
        4. Efficiency: Why You Must Use a Filter With the Traditional Class-D Modulation Scheme
        5. Effects of Applying a Square Wave Into a Speaker
        6. When to Use an Output Filter
      4. 9.3.4 Thermal and Short-Circuit Protection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Summing Input Signals with the TPA2005D1
        1. Summing Two Differential Input Signals
        2. Summing a Differential Input Signal and a Single-Ended Input Signal
        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 TPA2005D1 with Differential Input
        1. Design Requirements
        2. Detailed Design Procedure
          1. Component Selection
          2. Input Resistors (RI)
          3. Decoupling Capacitor (CS)
        3. Application Curves
      2. 10.2.2 TPA2005D1 with Differential Input and Input Capacitors
        1. Design Requirements
        2. Detailed Design Procedure
          1. Input Capacitors (CI)
      3. 10.2.3 TPA2005D1 with Single-Ended Input
        1. Design Requirements
        2. Detailed Design Procedure
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Decoupling Capacitors
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Component Location
      2. 12.1.2 Trace Width
      3. 12.1.3 MicroStar Junior™ BGA Specifications
    2. 12.2 Layout Examples
  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

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DGN|8
  • DRB|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10 Application and Implementation


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 for design assistance and join the audio amplifier discussion forum for additional information.

10.2 Typical Applications

These application circuits detail the recommended component selection and board configurations for the TPA2005D1 device.

10.2.1 TPA2005D1 with Differential Input

TPA2005D1 ai_Wireless_los369.gif Figure 40. Typical TPA2005D1 Differential Input for a Wireless Phone Design Requirements

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

Table 1. Design Requirements

Power Supply 5 V
Shutdown Input High > 2 V
Low < 0.8 V
Speaker 8 Ω Detailed Design Procedure Component Selection

Figure 40 shows the TPA2005D1 typical schematic with differential inputs and Figure 42 shows the TPA2005D1 with differential inputs and input capacitors, and Figure 43 shows the TPA2005D1 with single-ended inputs. Differential inputs should be used whenever possible because the single-ended inputs are much more susceptible to noise.

Table 2. Typical Component Values

RI 150 kΩ (±0.5%) 0402 Panasonic ERJ2RHD154V
CS 1 μF (+22%, -80%) 0402 Murata GRP155F50J105Z
CI (1) 3.3 nF (±10%) 0201 Murata GRP033B10J332K
(1) CI is only needed for single-ended input or if VICM is not between 0.5 V and VDD - 0.8 V. CI = 3.3 nF (with RI = 150 kΩ) gives a high-pass corner frequency of 321 Hz. Input Resistors (RI)

The input resistors (RI) set the gain of the amplifier according to equation Equation 20.

Equation 20. TPA2005D1 Q1_gain_los369.gif

Resistor matching is 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 close to the TPA2005D1 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 TPA2005D1 to operate at its best, and keeps a high voltage at the input making the inputs less susceptible to noise. Decoupling Capacitor (CS)

The TPA2005D1 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 TPA2005D1 is 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. Application Curves

TPA2005D1 tc_OutpwrSV_los369.gif Figure 41. Output Power vs Supply Voltage

10.2.2 TPA2005D1 with Differential Input and Input Capacitors

TPA2005D1 ai_InputCap_los369.gif Figure 42. TPA2005D1 Differential Input and Input Capacitors Design Requirements

Please see Design Requirements. Detailed Design Procedure

Please see Detailed Design Procedure. Input Capacitors (CI)

The TPA2005D1 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 (shown in Figure 40). 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 (shown in Figure 42), or if using a single-ended source (shown in Figure 43), input coupling capacitors are required.

The input capacitors and input resistors form a high-pass filter with the corner frequency, fc, determined in equation Equation 21.

Equation 21. TPA2005D1 Q2_fc_los369.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.

Equation Equation 22 is reconfigured to solve for the input coupling capacitance.

Equation 22. TPA2005D1 Q3_CI_los369.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, and causes pop. Any capacitor in the audio path should have a rating of X7R or better.

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.

10.2.3 TPA2005D1 with Single-Ended Input

TPA2005D1 ai_SingEnd_los369.gif Figure 43. TPA2005D1 Single-Ended Input Design Requirements

Please see Design Requirements. Detailed Design Procedure

Please see Detailed Design Procedure.