SBOS377L October   2006  – January 2020 OPA211

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Input Voltage Noise Density vs Frequency
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions: OPA211
    2.     Pin Functions: OPA2211
  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: OPA211 and OPA211A
    5. 6.5 Thermal Information: OPA2211 and OPA2211A
    6. 6.6 Electrical Characteristics: Standard Grade OPAx211A
    7. 6.7 Electrical Characteristics: High-Grade OPAx211
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Total Harmonic Distortion Measurements
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Operating Voltage
      2. 8.1.2 Input Protection
      3. 8.1.3 Noise Performance
      4. 8.1.4 Basic Noise Calculations
      5. 8.1.5 EMI Rejection
      6. 8.1.6 EMIRR +IN Test Configuration
      7. 8.1.7 Electrical Overstress
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 SON Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 TINA-TI™ (Free Software Download)
        2. 11.1.1.2 TI Precision Designs
        3. 11.1.1.3 WEBENCH® Filter Designer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Support Resources
    6. 11.6 Trademarks
    7. 11.7 Electrostatic Discharge Caution
    8. 11.8 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.1.3 Noise Performance

Figure 45 shows total circuit noise for varying source impedances with the operational amplifier in a unity-gain configuration (no feedback resistor network, and therefore no additional noise contributions). Two different operational amplifiers are shown with total circuit noise calculated. The OPAx211 has very low voltage noise, making the family a viable option for low source impedances (less than 2 kΩ). A similar precision operational amplifier, the OPA227, has somewhat higher voltage noise but lower current noise. It provides excellent noise performance at moderate source impedance (10 to 100 kΩ). Above 100 kΩ, a FET-input operational amplifier such as the OPA132 (very low current noise) may provide improved performance. The equation in Figure 45 is shown for the calculation of the total circuit noise.

NOTE

en = voltage noise, In = current noise, RS = source impedance, k = Boltzmann’s constant = 1.38 × 10–23 J/K, and T is temperature in K.
OPA211 OPA2211 ai_noise_perf_bos377.gifFigure 45. Noise Performance of the OPA211 and OPA227 in Unity-Gain Buffer Configuration