SLOS474E August   2005  – March 2016 TPA2005D1-Q1

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 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 Efficiency and Thermal Information
      3. 9.3.3 Eliminating the Output Filter With the TPA2005D1-Q1
        1. 9.3.3.1 Effect On Audio
        2. 9.3.3.2 Traditional Class-D Modulation Scheme
        3. 9.3.3.3 TPA2005D1-Q1 Modulation Scheme
        4. 9.3.3.4 Efficiency: Why You Must Use a Filter With The Traditional Class-D Modulation Scheme
        5. 9.3.3.5 Effects Of Applying a Square Wave Into a Speaker
        6. 9.3.3.6 When to Use an Output Filter
    4. 9.4 Device Functional Modes
      1. 9.4.1 Summing Input Signals With the TPA2005D1-Q1
        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
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 TPA2005D1-Q1 With Differential Input
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Component Selection
          2. 10.2.1.2.2 Input Resistors (RI)
          3. 10.2.1.2.3 Decoupling Capacitor (CS)
        3. 10.2.1.3 Application Curve
      2. 10.2.2 TPA2005D1-Q1 With Differential Input and Input Capacitors
        1. 10.2.2.1 Detailed Design Requirements
          1. 10.2.2.1.1 Input Capacitors (CI)
      3. 10.2.3 TPA2005D1-Q1 With Single-Ended Input
  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 8-Pin QFN (DRB) Layout
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Community Resource
    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

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 http://e2e.ti.com for design assistance.

10.2 Typical Application

10.2.1 TPA2005D1-Q1 With Differential Input

TPA2005D1-Q1 ai_Wireless_los474.gif Figure 38. Typical TPA2005D1-Q1 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 Requirements

PARAMETER EXAMPLE
Power Supply 5 V
Shutdown Input High > 2 V
Low < 0.8 V
Speaker 8 Ω

10.2.1.2 Detailed Design Procedure

10.2.1.2.1 Component Selection

Figure 38 shows the TPA2005D1-Q1 typical schematic with differential inputs, and Figure 40 shows the TPA2005D1-Q1 device with differential inputs and input capacitors, and Figure 41 shows the TPA2005D1-Q1 device 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

REF DES VALUE EIA SIZE MANUFACTURER PART NUMBER
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 needed only 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.

10.2.1.2.2 Input Resistors (RI)

The input resistors (RI) set the gain of the amplifier according to equation Equation 19.

Equation 19. TPA2005D1-Q1 Q1_gain_los474.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 TPA2005D1-Q1 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-Q1 to operate at its best and keeps a high voltage at the input, making the inputs less susceptible to noise.

10.2.1.2.3 Decoupling Capacitor (CS)

The TPA2005D1-Q1 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-Q1 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 also helps, but it is not required in most applications because of the high PSRR of this device.

10.2.1.3 Application Curve

TPA2005D1-Q1 tc_OutpwrSV_los369.gif Figure 39. Output Power vs Supply Voltage

10.2.2 TPA2005D1-Q1 With Differential Input and Input Capacitors

TPA2005D1-Q1 ai_InputCap_los474.gif Figure 40. TPA2005D1-Q1 Application Schematic With Differential Input And Input Capacitors

10.2.2.1 Detailed Design Requirements

10.2.2.1.1 Input Capacitors (CI)

The TPA2005D1-Q1device 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 38). 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 40), or if using a single-ended source (shown in Figure 41), input coupling capacitors are required.

The input capacitors and input resistors form a high-pass filter with the corner frequency, fc, determined in Equation 20.

Equation 20. TPA2005D1-Q1 Q2_fc_los474.gif

The value of the input capacitor is important to consider, as it directly affects the bass (low frequency) performance of the circuit.

Equation 21 is reconfigured to solve for the input coupling capacitance.

Equation 21. TPA2005D1-Q1 Q3_CI_los474.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 frequencies lower than the corner frequency.

For a flat low-frequency response, use large input coupling capacitors (1 μF).

10.2.3 TPA2005D1-Q1 With Single-Ended Input

TPA2005D1-Q1 ai_SingEnd_los474.gif Figure 41. TPA2005D1-Q1 Application Schematic With Single-Ended Input