SBOS831B December   2016  – June 2021 THS4552

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics: (VS+) – (VS–) = 5 V
    6. 6.6 Electrical Characteristics: (VS+) – (VS–) = 3 V
    7. 6.7 Typical Characteristics: (VS+) – (VS–) = 5 V
    8. 6.8 Typical Characteristics: (VS+) – (VS–) = 3 V
    9. 6.9 Typical Characteristics: 3 V to 5 V Supply Range
  7. 7 Parameter Measurement Information
    1. 7.1 Example Characterization Circuits
    2. 7.2 Output Interface Circuit for DC-Coupled Differential Testing
    3. 7.3 Output Common-Mode Measurements
    4. 7.4 Differential Amplifier Noise Measurements
    5. 7.5 Balanced Split-Supply Versus Single-Supply Characterization
    6. 7.6 Simulated Characterization Curves
    7. 7.7 Terminology and Application Assumptions
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Differential Open-Loop Gain and Output Impedance
      2. 8.3.2 Setting Resistor Values Versus Gain
      3. 8.3.3 I/O Headroom Considerations
      4. 8.3.4 Output DC Error and Drift Calculations and the Effect of Resistor Imbalances
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation from Single-Ended Sources to Differential Outputs
        1. 8.4.1.1 AC-Coupled Signal Path Considerations for Single-Ended Input to Differential Output Conversions
        2. 8.4.1.2 DC-Coupled Input Signal Path Considerations for Single-Ended to Differential Conversions
      2. 8.4.2 Operation from a Differential Input to a Differential Output
        1. 8.4.2.1 AC-Coupled, Differential-Input to Differential-Output Design Issues
        2. 8.4.2.2 DC-Coupled, Differential-Input to Differential-Output Design Issues
      3. 8.4.3 Input Overdrive Performance
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Noise Analysis
      2. 9.1.2 Factors Influencing Harmonic Distortion
      3. 9.1.3 Driving Capacitive Loads
      4. 9.1.4 Interfacing to High-Performance Precision ADCs
      5. 9.1.5 Operating the Power Shutdown Feature
      6. 9.1.6 Channel-to-Channel Crosstalk
      7. 9.1.7 Channel-to-Channel Mismatch
      8. 9.1.8 Designing Attenuators
      9. 9.1.9 The Effect of Adding a Feedback Capacitor
    2. 9.2 Typical Applications
      1. 9.2.1 An MFB Filter Driving an ADC Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Differential Transimpedance Output to a High-Grade Audio PCM DAC Application
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 ADC3k Driver with a 2nd-Order RLC Interstage Filter Application
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curve
  10. 10Power Supply Recommendations
    1. 10.1 Thermal Analysis
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Board Layout Recommendations
    2. 11.2 Layout Example
    3. 11.3 EVM Board
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 TINA-TI Simulation Model Features
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.1.1 Noise Analysis

The first step in the output noise analysis is to reduce the application circuit to the simplest form with equal feedback and gain setting elements to ground. Figure 9-1 shows the simplest analysis circuit with the FDA and resistor noise terms to be considered.

GUID-A8E963DE-7D14-41E5-9EC6-1EEA53C18949-low.gifFigure 9-1 FDA Noise Analysis Circuit

The noise powers are shown in Figure 9-1 for each term. When the RF and RG (or RI) terms are matched on each side, the total differential output noise is the root sum squared (RSS) of these separate terms. Using NG ≡ 1 + RF / RG, the total output noise is given by Equation 10. Each resistor noise term is a 4kT × R power (4kT = 1.6E-20J at 290K).

Equation 10. GUID-BC1568DA-EAB7-4120-8A7B-2D43656DA295-low.gif

The first term is simply the differential input spot noise times the noise gain, the second term is the input current noise terms times the feedback resistor (and because there are two uncorrelated current noise terms, the power is two times one of them), and the last term is the output noise resulting from both the RF and RG resistors, at again twice the value for the output noise power of each side added together. Running a wide sweep of gains when holding RF close to 1 kΩ and setting the input up for a 50 Ω match gives the standard values and resulting noise listed in Table 9-1.

Note that when the gain increases, the input-referred noise approaches only the gain of the FDA input voltage noise term at 3.3 nV/√ Hz.

Table 9-1 Swept Gain of the Output- and Input-Referred Spot Noise Calculations
GAIN (V/V)RF (Ω)RG1 (Ω)RT (Ω)RG2 (Ω)ZIN (Ω)AV (V/V)EO (nV/√ Hz)EI (nV/√ Hz)
0.110001000049.91000049.660.09965770
1100097651.1100049.21.009610.410.4
2102049952.352348.91.98813.96.95
510001875921550.25.057234.6
10102088.769.811850.610.0936.43.64