SLOS733B January   2012  – April 2016 TPA2080D1

PRODUCTION DATA.  

  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. 9.3.1.1 Advantages of Fully Differential Amplifiers
      2. 9.3.2 Short-Circuit Auto-Recovery
      3. 9.3.3 Operation With DACs and CODECs
      4. 9.3.4 Speaker Load Limitation
      5. 9.3.5 Filter-Free Operation and Ferrite Bead Filters.
      6. 9.3.6 Boost Converter Auto Pass Through (APT)
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 TPA2080D1 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 Surface Mount Inductor
          2. 10.2.1.2.2 Inductor Selection
          3. 10.2.1.2.3 Surface Mount Capacitors
          4. 10.2.1.2.4 Boost Converter Capacitor Selection
          5. 10.2.1.2.5 Decoupling Capacitors
          6. 10.2.1.2.6 Input Capacitors
          7. 10.2.1.2.7 Boost Converter Component Section
        3. 10.2.1.3 Application Curves
      2. 10.2.2 TPA2080D1 With Single-Ended Signals.
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 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
      2. 12.1.2 Thermal Considerations
      3. 12.1.3 Pad Size
    2. 12.2 Layout Example
  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
    1. 14.1 Package Dimensions

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. 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 Application

10.2.1 TPA2080D1 With Differential Input Signal

TPA2080D1 Differential_app_SLOS733.gif Figure 23. Typical Application Schematic With Differential Input Signals

10.2.1.1 Design Requirements

For this design example, use the parameters listed in Table 2.

Table 2. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
Power supply 3.6 V
Enable inputs High > 1.3 V
Low < 0.6 V
Speaker 8 Ω

10.2.1.2 Detailed Design Procedure

10.2.1.2.1 Surface Mount Inductor

Working inductance decreases as inductor current increases. if the drop in working inductance is severe enough, it may cause the boost converter to become unstable, or cause the TPA2080D1 to reach its current limit at a lower output power than expected. Inductor vendors specify currents at while inductor values decrease by a specific percentage. This can vary from 10% to 35%. Inductance is also affected by DC current and temperature.

10.2.1.2.2 Inductor Selection

Inductor current rating is determined by the requirements of the load. The inductance is determined by two factors: the minimum value required for stability and the maximum ripple current permitted in the application. Use Equation 1 to determine the required current rating. Equation 1 shows the approximate relationship between the average inductor current, IL, to the load current, load voltage, and input voltage (IPVDD, PVDD, and VBAT, respectively). Insert IPVDD, PVDD, and VBAT into Equation 1 and solve for IL. The inductor must maintain at least 90% of its initial inductance value at this current.

Equation 1. TPA2080D1 EQ1_IL_los638.gif

Ripple current, ΔIL, is peak-to-peak variation in inductor current. Smaller ripple current reduces core losses in the inductor and reduces the potential for EMI. Use Equation 2 to determine the value of the inductor, L. Equation 2 shows the relationship between inductance L, VBAT, PVDD, the switching frequency, fBOOST, and ΔIL. Insert the maximum acceptable ripple current into Equation 2 and solve for L.

Equation 2. TPA2080D1 EQ2_L_los638.gif

ΔIL is inversely proportional to L. Minimize ΔIL as much as is necessary for a specific application. Increase the inductance to reduce the ripple current. Do not use greater than 4.7 μH, as this prevents the boost converter from responding to fast output current changes properly. If using above 3.3 µH, then use at least 10-µF capacitance on PVDD to ensure boost converter stability.

The typical inductor value range for the TPA2080D1 is 2.2 μH to 3.3 µH. Select an inductor with less than 0.5-Ω DC resistance, DCR. Higher DCR reduces total efficiency due to an increase in voltage drop across the inductor.

Table 3. Sample Inductors

L
(µH)
SUPPLIER COMPONENT CODE SIZE
(LxWxH mm)
DCR TYP
(mΩ)
ISAT MAX
(A)
C RANGE
2.2 Chilisin Electronics Corp. CLCN252012T-2R2M-N 2.5 x 2 x 1.2 105 1.2 10 to 22 µF, 16 V
10 to 22 µF, 10 V
2.2 Toko 1239AS-H-2R2N=P2 2.5 x 2 x 1.2 96 2.3
2.2 Coilcraft XFL4020-222MEC 4 x 4 x 2.15 22 3.5
3.3 Toko 1239AS-H-3R3N=P2 2.5 x 2 x 1.2 160 2 10 to 22 µF, 10 V
3.3 Coilcraft XFL4020-332MEC 4 x 4 x 2.15 35 2.8

10.2.1.2.3 Surface Mount Capacitors

Temperature and applied DC voltage influence the actual capacitance of high-K materials. Table 4 shows the relationship between the different types of high-K materials and their associated tolerances, temperature coefficients, and temperature ranges. Notice that a capacitor made with X5R material can lose up to 15% of its capacitance within its working temperature range.

In an application, the working capacitance of components made with high-K materials is generally much lower than nominal capacitance. A worst-case result with a typical X5R material might be –10% tolerance, –15% temperature effect, and –45% DC voltage effect at 50% of the rated voltage. This particular case would result in a working capacitance of 42% (0.9 × 0.85 × 0.55) of the nominal value.

Select high-K ceramic capacitors according to the following rules:

  1. Use capacitors made of materials with temperature coefficients of X5R, X7R, or better.
  2. Use capacitors with DC voltage ratings of at least twice the application voltage. Use minimum 10-V capacitors for the TPA2080D1.
  3. Choose a capacitance value at least twice the nominal value calculated for the application. Multiply the nominal value by a factor of 2 for safety. If a 10-μF capacitor is required, use 20 µF.

The preceding rules and recommendations apply to capacitors used in connection with the TPA2080D1. The TPA2080D1 cannot meet its performance specifications if the rules and recommendations are not followed.

Table 4. Typical Tolerance and Temperature Coefficient of Capacitance by Material

MATERIAL COG / NPO X7R X5R
Typical tolerance ±5% ±10% 80% or –20%
Temperature ±30 ppm ±15% 22% or –82%
Temperature range, °C –55°C to 125°C –55°C to 125°C –30°C to 85°C

10.2.1.2.4 Boost Converter Capacitor Selection

The value of the boost capacitor is determined by the minimum value of working capacitance required for stability and the maximum voltage ripple allowed on PVDD in the application. Working capacitance refers to the available capacitance after derating the capacitor value for DC bias, temperature, and aging. Do not use any component with a working capacitance less than 6.8 µF. This corresponds to a 10-μF, 16-V capacitor or a 10-μF, 10-V capacitor.

Do not use above 22-μF capacitance as it will reduce the boost converter response time to large output current transients.

Equation 3 shows the relationship between the boost capacitance, C, to load current, load voltage, ripple voltage, input voltage, and switching frequency (IPVDD, PVDD, ΔV, VBAT, and fBOOST respectively).

Insert the maximum allowed ripple voltage into Equation 3 and solve for C. The 1.5 multiplier accounts for capacitance loss due to applied DC voltage and temperature for X5R and X7R ceramic capacitors.

Equation 3. TPA2080D1 EQ3_C_los638.gif

10.2.1.2.5 Decoupling Capacitors

The TPA2080D1 is a high-performance Class-D audio amplifier that requires adequate power supply decoupling. Adequate power supply decoupling to ensures that the efficiency is high and total harmonic distortion (THD) is low.

Place a low equivalent-series-resistance (ESR) ceramic capacitor, typically 0.1 µF, within 2 mm of the VBAT ball. Use X5R and X7R ceramic capacitors. This choice of capacitor and placement helps with higher frequency transients, spikes, or digital hash on the line. Additionally, placing this decoupling capacitor close to the TPA2080D1 is important, as any parasitic resistance or inductance between the device and the capacitor causes efficiency loss. In addition to the 0.1-μF ceramic capacitor, place a 2.2-µF to 10-µF capacitor on the VBAT supply trace. This larger capacitor acts as a charge reservoir, providing energy faster than the board supply, thus helping to prevent any droop in the supply voltage.

10.2.1.2.6 Input Capacitors

Input audio DC decoupling capacitors are recommended. The input capacitors and TPA2080D1 input impedance form a high-pass filter with the corner frequency, fC, determined in Equation 4.

Any mismatch in capacitance between the two inputs will cause a mismatch in the corner frequencies. Severe mismatch may also cause turnon pop noise. Choose capacitors with a tolerance of ±10% or better. Use X5R and X7R ceramic capacitors.

Equation 4. TPA2080D1 EQ_fc_los638.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. Not using input capacitors can increase output offset.

10.2.1.2.7 Boost Converter Component Section

The critical external components are summarized in Table 5.

Table 5. Recommended Values

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Boost converter inductor At 30% rated DC bias current of the inductor 1.5 2.2 4.7 µH
Input capacitor 1 10 µF
Boost converter output capacitor Working capacitance biased at boost output voltage, if 4.7-µH inductor is chosen, then minimum capacitance is 10 µF 4.7 22 µF

10.2.1.3 Application Curves

For application curves, see the figures listed in Table 6.

Table 6. Table of Graphs

DESCRIPTION FIGURE NUMBER
Output Power vs Supply Voltage Figure 1
THD+N vs Frequency Figure 5
THD+N vs Output Power Figure 7
Total Power Dissipation vs Output Power Figure 11

10.2.2 TPA2080D1 With Single-Ended Signals.

TPA2080D1 Single_ended_app_SLOS733.gif Figure 24. Typical Application Schematic With Single-Ended Input Signal

10.2.2.1 Design Requirements

For this design example, use the parameters listed in Table 2.

10.2.2.2 Detailed Design Procedure

For the design procedure see Detailed Design Procedure.

10.2.2.3 Application Curves

For application curves, see the figures listed in Table 6.