SBOS618I December   2013  – May 2018 OPA172 , OPA2172 , OPA4172

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      JFET-Input Low-Noise Amplifier
      2.      Superior THD Performance
  4. 4 Revision History
  5. 5 Device Comparison
    1. 5.1 Device Comparison
    2. 5.2 Device Family Comparison
  6. 6 Pin Configuration and Functions
    1.     Pin Functions: OPA172
    2.     Pin Functions: OPA2172 and OPA4172
  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: OPA172
    5. 7.5 Thermal Information: OPA2172
    6. 7.6 Thermal Information: OPA4172
    7. 7.7 Electrical Characteristics
    8. 7.8 Typical Characteristics: Table of Graphs
    9. 7.9 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 EMI Rejection
      2. 8.3.2 Phase-Reversal Protection
      3. 8.3.3 Capacitive Load and Stability
    4. 8.4 Device Functional Modes
      1. 8.4.1 Common-Mode Voltage Range
      2. 8.4.2 Electrical Overstress
      3. 8.4.3 Overload Recovery
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Capacitive Load Drive Solution Using an Isolation Resistor
        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 Bidirectional Current Source
      3. 9.2.3 JFET-Input Low-Noise Amplifier
  10. 10Power-Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 TINA-TI (Free Software Download)
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Related Links
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.1 Capacitive Load Drive Solution Using an Isolation Resistor

The OPA172 can be used capacitive loads such as cable shields, reference buffers, MOSFET gates, and diodes. The circuit uses an isolation resistor (RISO) to stabilize the output of an op amp. RISO modifies the open-loop gain of the system to ensure the circuit has sufficient phase margin.

OPA172 OPA2172 OPA4172 ai_refdes_blockdia_bos618.gifFigure 47. Unity-Gain Buffer with RISO Stability Compensation