SBOS932C January   2020  – March 2021 THP210

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
    6. 6.6 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Characterization Configuration
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Super-Beta Input Bipolar Transistors
      2. 8.3.2 Power Down
      3. 8.3.3 Flexible Gain Setting
      4. 8.3.4 Amplifier Overload Power Limit
      5. 8.3.5 Unity Gain Stability
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 I/O Headroom Considerations
      2. 9.1.2 DC Precision Analysis
        1. 9.1.2.1 DC Error Voltage at Room Temperature
        2. 9.1.2.2 DC Error Voltage Over Temperature
      3. 9.1.3 Noise Analysis
      4. 9.1.4 Mismatch of External Feedback Network
      5. 9.1.5 Operating the Power-Down Feature
      6. 9.1.6 Driving Capacitive Loads
      7. 9.1.7 Driving Differential ADCs
        1. 9.1.7.1 RC Filter Selection (Charge Kickback Filter)
        2. 9.1.7.2 Settling Time Driving the ADC Sample-and-Hold Operating Behavior
        3. 9.1.7.3 THD Performance
    2. 9.2 Typical Applications
      1. 9.2.1 MFB Filter
        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 ADS891x With Single-Ended RC Filter Stage
        1. 9.2.2.1 Design Requirements
          1. 9.2.2.1.1 Measurement Results
      3. 9.2.3 Attenuation Configuration Drives the ADS8912B
        1. 9.2.3.1 Design Requirements
          1. 9.2.3.1.1 Measurement Results
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Board Layout Recommendations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    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

7.1 Characterization Configuration

The THP210 is a fully differential amplifier (FDA) configuration that offers high dc precision, very low noise and harmonic distortion in a single, low-power amplifier. The FDA is a flexible device where the main aim is to provide a purely differential output signal centered on a user-configurable, common-mode voltage that is usually matched to the input common-mode voltage required by an analog-to-digital converter (ADC). The circuit used for characterization of the differential-to-differential performance is seen in Figure 7-1

GUID-20200821-CA0I-3FKT-T525-29GVGLLDKTSZ-low.gif Figure 7-1 Differential Source to a Differential Gain of a 1-V/V Test Circuit

A similar circuit is used for single-ended to differential measurements, as shown in Figure 7-2.

GUID-E778F7DD-99F8-43C5-9CB4-B0297B29549A-low.gifFigure 7-2 Single-ended Source to Differential Gain of 1-V/V Test Circuit

The characterization plots fix the RF (RF1 = RF2) value at 2 kΩ, unless otherwise noted. This value can be adjusted to match the system design parameters with the following considerations in mind:

  • The current required to drive RF from the peak output voltage to the input common-mode voltage add to the overall output load current. If the total current (current through RF + current through RL) exceeds the current limit conditions, the device enters a current limit, causing the output voltage to collapse.
  • High feedback resistor values (RF > 100 kΩ) interact with the amplifier input capacitance to create a zero in the feedback network. Compensation must be added to account for potential source of instability; see the TI Precision Labs FDA Stability Training for guidance on designing an appropriate compensation network.