SLOS930B November   2015  – November 2019 THS4541-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Single to Differential Gain of 2, 2-VPP Output
  4. 4 Revision History
  5. 5 Device Comparison Table
  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+) – Vs– = 5 V
    6. 7.6 Electrical Characteristics: (Vs+) – Vs– = 3 V
    7. 7.7 Typical Characteristics
      1. 7.7.1 5-V Single Supply
      2. 7.7.2 3-V Single Supply
      3. 7.7.3 3-V to 5-V Supply Range
  8. 8 Parameter Measurement Information
    1. 8.1 Example Characterization Circuits
    2. 8.2 Frequency-Response Shape Factors
    3. 8.3 I/O Headroom Considerations
    4. 8.4 Output DC Error and Drift Calculations and the Effect of Resistor Imbalances
    5. 8.5 Noise Analysis
    6. 8.6 Factors Influencing Harmonic Distortion
    7. 8.7 Driving Capacitive Loads
    8. 8.8 Thermal Analysis
  9. 9 Detailed Description
    1. 9.1 Overview
      1. 9.1.1 Terminology and Application Assumptions
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Differential I/O
      2. 9.3.2 Power-Down Control Pin (PD)
        1. 9.3.2.1 Operating the Power Shutdown Feature
      3. 9.3.3 Input Overdrive Operation
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operation from Single-Ended Sources to Differential Outputs
        1. 9.4.1.1 AC-Coupled Signal Path Considerations for Single-Ended Input to Differential Output Conversion
        2. 9.4.1.2 DC-Coupled Input Signal Path Considerations for Single-Ended to Differential Conversion
        3. 9.4.1.3 Resistor Design Equations for the Single-Ended to Differential Configuration of the FDA
        4. 9.4.1.4 Input Impedance for the Single-Ended to Differential FDA Configuration
      2. 9.4.2 Differential-Input to Differential-Output Operation
        1. 9.4.2.1 AC-Coupled, Differential-Input to Differential-Output Design Issues
        2. 9.4.2.2 DC-Coupled, Differential-Input to Differential-Output Design Issues
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Designing Attenuators
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curve
      2. 10.2.2 Interfacing to High-Performance ADCs
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
        1. 13.1.1.1 TINA Simulation Model Features
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.4.1.2 DC-Coupled Input Signal Path Considerations for Single-Ended to Differential Conversion

The output considerations remain the same as for the AC-coupled design. Again, the input can be DC coupled while the output is AC coupled. A DC-coupled input with an AC-coupled output might have some advantages to move the input Vicm down if the source is ground referenced. When the source is DC coupled into the THS4541-Q1 (see Figure 63), both sides of the input circuit must be DC coupled to retain differential balance. Normally, the nonsignal input side has an Rg element biased to whatever the source midrange is expected to be. Providing this midscale reference gives a balanced differential swing around Vocm at the outputs. Often, Rg2 is simply grounded for DC-coupled, bipolar-input applications. This configuration gives a balanced differential output if the source is swinging around ground. If the source swings from ground to some positive voltage, grounding Rg2 gives a unipolar output differential swing from both outputs at Vocm (when the input is at ground) to one polarity of swing. Biasing Rg2 to an expected midpoint for the input signal creates a differential output swing around Vocm.

One significant consideration for a DC-coupled input is that Vocm sets up a common-mode bias current from the output back through Rf and Rg to the source on both sides of the feedback. Without input balancing networks, the source must sink or source this DC current. After the input signal range and biasing on the other Rg element is set, check that the voltage divider from Vocm to Vin through Rf and Rg (and possibly Rs) establishes an input Vicm at the device input pins that is in range. If the average source is at ground, the negative rail input stage for the THS4541-Q1 is in range for applications using a single positive supply and a positive output Vocm setting because this DC current lifts the average FDA input summing junctions up off of ground to a positive voltage (the average of the V+ and V– input pin voltages on the FDA).