SBOS365G may   2006  – may 2023 OPA2365 , OPA365

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information: OPA365
    5. 7.5 Thermal Information: OPA2365
    6. 7.6 Electrical Characteristics
    7. 7.7 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Rail-to-Rail Input
      2. 8.3.2 Input and ESD Protection
      3. 8.3.3 Capacitive Loads
      4. 8.3.4 Achieving an Output Level of Zero Volts (0 V)
      5. 8.3.5 Active Filtering
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Basic Amplifier Configurations
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
    3. 9.3 System Examples
      1. 9.3.1 Driving an Analog-to-Digital Converter
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 PSpice® for TI
        2. 10.1.1.2 TINA-TI™ Simulation Software (Free Download)
        3. 10.1.1.3 DIP-Adapter-EVM
        4. 10.1.1.4 DIYAMP-EVM
        5. 10.1.1.5 TI Reference Designs
        6. 10.1.1.6 Filter Design Tool
    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. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.5 Active Filtering

The OPAx365 are an excellent choice for active filter applications requiring a wide bandwidth, fast slew rate, low-noise, single-supply operational amplifier. Figure 8-5 shows a 500-kHz, second-order, low-pass filter using the multiple-feedback (MFB) topology. The components have been selected to provide a maximally-flat Butterworth response. Beyond the cutoff frequency, rolloff is −40 dB/dec. The Butterworth response is great for applications requiring predictable gain characteristics such as the antialiasing filter used ahead of an ADC.

GUID-1A96896A-1697-4B2A-A8D8-DCF910A08317-low.gif Figure 8-5 Second-Order Butterworth, 500-kHz Low-Pass Filter

One point to observe when considering the MFB filter is that the output is inverted, relative to the input. If this inversion is not required, or not desired, a noninverting output can be achieved through one of these options:

  • Add an inverting amplifier.
  • Add an additional second-order MFB stage.
  • Use a noninverting filter topology such as Sallen-Key.

The Sallen-Key topology is shown in Figure 8-6.

GUID-44E9E2E2-840D-4EB1-8C0A-4D983091E279-low.gif Figure 8-6 Configured as a Three-Pole, 20-kHz, Sallen-Key Filter