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

9.2.4.1 AC-Coupled, Differential-Input to Differential-Output Design Issues

There are two typical ways to use the THS4531A family with an AC-coupled differential source. In the first method, the source is differential and can be coupled in through two blocking capacitors. The second method uses either a single-ended or a differential source and couples in through a transformer (or balun). Figure 93 shows a typical blocking capacitor approach to a differential input. An optional differential-input termination resistor (RM) is included in this design. This RM element allows the input RG resistors to be scaled up while still delivering lower differential input impedance to the source. In this example, the RG elements sum to show a 500-Ω differential impedance, while the RM element combines in parallel to give a net 100-Ω, AC-coupled, differential impedance to the source. Again, the design proceeds ideally by selecting the RF element values, then the RG to set the differential gain, then an RM element (if needed) to achieve the target input impedance. Alternatively, the RM element can be eliminated, the RG elements set to the desired input impedance, and RF set to the get the differential gain (RF / RG).

THS4531A Example_Down_Converting_Mixer.gifFigure 93. Example Down-Converting Mixer Delivering an AC-Coupled Differential Signal to the THS4531A

The DC biasing here is very simple. The output VOCM is set by the input control voltage; and because there is no DC-current path for the output common-mode voltage, that DC bias also sets the input pins common-mode operating points.