SLOS375B August   2014  – February 2024 THS4541

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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 5-V Single Supply
    8. 6.8 Typical Characteristics: 3-V Single Supply
    9. 6.9 Typical Characteristics: 3-V to 5-V Supply Range
  8. 7 Parameter Measurement Information
    1. 7.1 Example Characterization Circuits
    2. 7.2 Frequency-Response Shape Factors
    3. 7.3 I/O Headroom Considerations
    4. 7.4 Output DC Error and Drift Calculations and the Effect of Resistor Imbalances
    5. 7.5 Noise Analysis
    6. 7.6 Factors Influencing Harmonic Distortion
    7. 7.7 Driving Capacitive Loads
    8. 7.8 Thermal Analysis
  9. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Terminology and Application Assumptions
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Differential I/O
      2. 8.3.2 Power-Down Control Pin (PD)
        1. 8.3.2.1 Operating the Power Shutdown Feature
      3. 8.3.3 Input Overdrive Operation
    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 Conversion
        2. 8.4.1.2 DC-Coupled Input Signal Path Considerations for Single-Ended to Differential Conversion
        3. 8.4.1.3 Resistor Design Equations for the Single-Ended to Differential Configuration of the FDA
        4. 8.4.1.4 Input Impedance for the Single-Ended to Differential FDA Configuration
      2. 8.4.2 Differential-Input to Differential-Output Operation
        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
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Designing Attenuators
        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 Interfacing to High-Performance ADCs
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curve
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 TINA Simulation Model Features
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RUN|10
  • RGT|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.2.2.2 Detailed Design Procedure

The THS4541 provides a very flexible element for interfacing from a variety of sources to a wide range of ADCs. Because all precision and high-speed ADCs require a differential input on a common-mode voltage, this design is the primary application for the THS4541.

The THS4541 provides a simple interface to a wide variety of precision SAR, ΔΣ, or higher-speed pipeline ADCs. To deliver the exceptional distortion at the output pins, considerably wider bandwidth than typically required in the signal path to the ADC inputs is provided by the THS4541. For instance, the gain of 2 single-ended to differential design example provides approximately a 500-MHz, small-signal bandwidth. Even if the source signal is Nyquist bandlimited, this broad bandwidth can possibly integrate enough THS4541 noise to degrade the SNR through the ADC if the broadband noise is not bandlimited between the amplifier and ADC.

Figure 9-4 shows an example DC-coupled, gain of 2 interface with a controlled, interstage-bandwidth filter implemented on the demonstration board for the JESD digital-output interface, ADC34J22 (a 50-MSPS, quad, 12-bit ADC). This board uses is called the DEV-ADC34J22 ADC HSMC MODULE with complete documentation at dallaslogic.com.

Designed for a DC-coupled 50Ω input match, this design starts with a 499-Ω feedback resistor, and provides a gain of 2.35V/V to the THS4541 output pins. The third-order interstage, low-pass filter provides a 20-MHz Bessel response with a 0.85 V/V insertion loss to the ADC, providing a net gain of 2 V/V from board edge to the ADC inputs. Although the THS4541 can absorb overdrives, an external protection element is added using the BAV99 low-capacitance device, shown in Figure 9-4. For DC-coupled testing, pins 1 and 2 are jumpered together. When the source is an AC-coupled, 50-Ω source, pins 2 and 3 are jumpered to maintain differential balance. FFT testing normally uses a bandpass filter into the board; an AC-coupled source. A typical 5-MHz, full-scale, single-tone FFT is shown in Figure 9-5, where the jumper is placed from pins 2 to 3. The reported SNR of 70.09 dBFs is only a slight reduction from the tested ADC-only performance of 70.42 dBFs, showing the value of the interstage noise bandwidth limiting filter. The exceptionally low harmonic distortion for the THS4541 also shows up in the very low SFDR and THD shown in Figure 9-5. This 96-dB SFDR and 92.83-dB THD are comparable to the ADC-only test results.