SBOA605 October   2025 OPA323

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2A Reusable Schematic
  6. 3Create a Project
    1. 3.1 Project Hierarchy
  7. 4Schematic Drawing for Increased Readability
    1. 4.1 Placing Passive Components
    2. 4.2 Parameters
    3. 4.3 Place Power Supplies
    4. 4.4 Wiring
    5. 4.5 Organizing for the User Experience
  8. 5Simulation Profile Setup
    1. 5.1 Aiding in Convergence
      1. 5.1.1 Modeling Application
    2. 5.2 Powerful Post-Processing
  9. 6Summary
  10. 7References

2 A Reusable Schematic

Once a repeatable procedure is identified, the next step is to find a schematic configuration that works for a majority of circuit configurations.

In this example, the most robust open loop configuration for op amps is the double-break shown in Method 3 which accounts for interaction between output impedance of the op amp to the feedback network (disadvantage of Method 1); and interaction between the feedback network and the parasitic impedance of the inputs (disadvantage of Method 2).

Methods for Pseudo Open-Loop Configuration for Op Amp CircuitsFigure 2-1 Methods for Pseudo Open-Loop Configuration for Op Amp Circuits

Method 3 is a preferred choice for PSpice®-for-TI’s re-usability as the main drawback is the complexity in the schematic in setup. For additional information on this method, see “Breaking loop on differential amplifier” video on ti.com.