SLOS823D December   2012  – March 2020 THS4531A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     1-kHz FFT Plot on Audio Analyzer
  4. 4 Revision History
  5. 5 Related Products
  6. 6 Pin Configuration and Functions
    1.     Pin 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: VS = 2.7 V
    6. 7.6 Electrical Characteristics: VS = 5 V
    7. 7.7 Typical Characteristics
      1. 7.7.1 Typical Characteristics: VS = 2.7 V
      2. 7.7.2 Typical Characteristics: VS = 5 V
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Common-Mode Voltage Range
        1. 8.3.1.1 Setting the Output Common-Mode Voltage
      2. 8.3.2 Power Down
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1  Frequency Response, and Output Impedance
      2. 9.1.2  Distortion
      3. 9.1.3  Slew Rate, Transient Response, Settling Time, Overdrive, Output Voltage, and Turnon and Turnoff Time
      4. 9.1.4  Common-Mode and Power Supply Rejection
      5. 9.1.5  VOCM Input
      6. 9.1.6  Balance Error
      7. 9.1.7  Single-Supply Operation
      8. 9.1.8  Low-Power Applications and the Effects of Resistor Values on Bandwidth
      9. 9.1.9  Driving Capacitive Loads
      10. 9.1.10 Audio Performance
      11. 9.1.11 Audio On and Off Pop Performance
    2. 9.2 Typical Applications
      1. 9.2.1 SAR ADC Performance: THS4531A and ADS8321 Combined Performance
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Audio ADC Driver Performance: THS4531A and PCM4204 Combined Performance
        1. 9.2.2.1 Detailed Design Procedure
        2. 9.2.2.2 Application Curves
      3. 9.2.3 SAR ADC Performance: THS4531A and ADS7945 Combined Performance
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curve
      4. 9.2.4 Differential-Input to Differential-Output Amplifier
        1. 9.2.4.1 AC-Coupled, Differential-Input to Differential-Output Design Issues
      5. 9.2.5 Single-Ended to Differential FDA Configuration
        1. 9.2.5.1 Input Impedance
      6. 9.2.6 Single-Ended Input to Differential Output Amplifier
        1. 9.2.6.1 AC-Coupled Signal Path Considerations for Single-Ended Input to Differential Output Conversion
        2. 9.2.6.2 DC-Coupled Input Signal Path Considerations for Single-Ended to Differential Conversion
        3. 9.2.6.3 Resistor Design Equations for the Single-Ended to Differential Configuration of the FDA
      7. 9.2.7 Differential Input to Single-Ended Output Amplifier
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.1 Application Information

Figure 70 shows the general test circuit built on the EVM that was used for testing the THS4531A. For simplicity, power supply decoupling is not shown – see Layout for recommendations. Depending on the test conditions, component values are changed per Table 4 and Table 5, or as otherwise noted. Some of the signal generators used are AC-coupled 50-Ω sources and a 0.22-µF capacitor and 49.9-Ω resistor to ground are inserted across RIT on the un-driven or alternate input as shown to balance the circuit. A split-power supply is used to ease the interface to common lab test equipment, but if properly biased, the amplifier can be operated single-supply as described in the applications section with no impact on performance. For most of the tests, the devices are tested with single ended input and a transformer on the output to convert the differential output to single ended because common lab test equipment have single ended inputs and outputs. Performance is the same or better with differential input and differential output.

THS4531A General_Test_Circuit_los823.gifFigure 70. General Test Circuit

Table 4. Gain Component Values for Single-Ended Input(1)

GAIN RF RG RIT
1 V/V 2 kΩ 2 kΩ 51.1 Ω
2 V/V 2 kΩ 1 kΩ 52.3 Ω
5 V/V 2 kΩ 392 Ω 53.6 Ω
10 V/V 2 kΩ 187 Ω 57.6 Ω
(1) Components are chosen to achieve gain and 50-Ω input termination. Resistor values shown are closest standard values so gains are approximate.

Table 5. Load Component Values For 1:1 Differential to Single-Ended Output Transformer(1)

RL RO ROT ATTEN (dB)
100 Ω 25 Ω open 6
200 Ω 84.5 Ω 71.5 Ω 16.7
500 Ω 237 Ω 56.2 Ω 25.6
1 kΩ 487 Ω 52.3 Ω 31.8
2 kΩ 976 Ω 51.1 Ω 38
(1) The total load includes 50-Ω termination by the test equipment. Components are chosen to achieve load and 50-Ω line termination through a 1:1 transformer. Resistor values shown are closest standard values so loads are approximate.

Because of the voltage divider on the output formed by the load component values, the output of the amplifier is attenuated. The column ATTEN in Table 5 shows the attenuation expected from the resistor divider. When using a transformer at the output as shown in Figure 70, the signal has slightly more loss because of transformer insertion loss, and these numbers are approximate. The standard output load used for most tests is 2 kΩ with associated 38 dB of loss.