OrCAD PSpice® User's Guide Copyright © 1998 OrCAD, Inc. All rights reserved. Trademarks OrCAD, OrCAD Layout, OrCAD Express, OrCAD Capture, OrCAD PSpice, and OrCAD PSpice A/D are registered trademarks of OrCAD, Inc. OrCAD Capture CIS, and OrCAD Express CIS are trademarks of OrCAD, Inc. Microsoft, Visual Basic, Windows, Windows NT, and other names of Microsoft products referenced herein are trademarks or registered trademarks of Microsoft Corporation. All other brand and product names mentioned herein are used for identification purposes only, and are trademarks or registered trademarks of their respective holders. Part Number 60-30-636 First edition 30 November 1998 Technical Support Corporate offices OrCAD Japan K.K. OrCAD UK Ltd. Fax General email Technical Support email World Wide Web OrCAD Design Network (ODN) (503) 671-9400 (503) 671-9500 81-45-621-1911 44-1256-381-400 (503) 671-9501 info@orcad.com techsupport@orcad.com http://www.orcad.com http://www.orcad.com/odn 9300 SW Nimbus Ave. Beaverton, OR 97008 USA Contents Before you begin xxiii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii xxiv . xxv . xxv xxvi xxvii xxviii xxviii . xxix Welcome to OrCAD . . . . . . . . . OrCAD PSpice overview . . . . . . How to use this guide . . . . . . . . Typographical conventions . . Related documentation . . . . . . . Online Help . . . . . . . . . . . If you have the demo CD-ROM OrCAD demo CD-ROM . . What's New . . . . . . . . . . . . . Part one Chapter 1 Simulation primer Things you need to know 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 3 3 3 4 5 6 6 7 8 8 9 9 9 10 Chapter overview . . . . . . . . . . . . . . . . . What is PSpice? . . . . . . . . . . . . . . . . . . Analyses you can run with PSpice . . . . . . . . Basic analyses . . . . . . . . . . . . . . . . . DC sweep & other DC calculations . . . AC sweep and noise . . . . . . . . . . . Transient and Fourier . . . . . . . . . . . Advanced multi-run analyses . . . . . . . . Parametric and temperature . . . . . . . Monte Carlo and sensitivity/worst-case Analyzing waveforms with PSpice . . . . . . . What is waveform analysis? . . . . . . . . . Using PSpice with other OrCAD programs . . . Using Capture to prepare for simulation . What is the Stimulus Editor? . . . . . . . . What is the Model Editor? . . . . . . . . . . Contents Files needed for simulation . . . . . . . . . . . . . . . Files that Capture generates . . . . . . . . . . . . Netlist file . . . . . . . . . . . . . . . . . . . . . Circuit file . . . . . . . . . . . . . . . . . . . . Other files that you can configure for simulation Model library . . . . . . . . . . . . . . . . . . . Stimulus file . . . . . . . . . . . . . . . . . . . Include file . . . . . . . . . . . . . . . . . . . . Configuring model library, stimulus, and include files . . . . . . . . . . . . . . . Files that PSpice generates . . . . . . . . . . . . . . . Waveform data file . . . . . . . . . . . . . . . PSpice output file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 10 11 11 11 12 13 13 13 14 14 14 Chapter 2 Simulation examples 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 16 21 22 22 24 25 26 26 28 31 32 36 37 37 39 41 42 43 45 48 49 51 Chapter overview . . . . . . . . . . . . . . . . . . . . . . . Example circuit creation . . . . . . . . . . . . . . . . . . . . Finding out more about setting up your design . . . . Running PSpice . . . . . . . . . . . . . . . . . . . . . . . . . Performing a bias point analysis . . . . . . . . . . . . . Using the simulation output file . . . . . . . . . . . . . Finding out more about bias point calculations . . . . DC sweep analysis . . . . . . . . . . . . . . . . . . . . . . . Setting up and running a DC sweep analysis . . . . . . Displaying DC analysis results . . . . . . . . . . . . . . Finding out more about DC sweep analysis . . . . . . Transient analysis . . . . . . . . . . . . . . . . . . . . . . . Finding out more about transient analysis . . . . . . . AC sweep analysis . . . . . . . . . . . . . . . . . . . . . . . Setting up and running an AC sweep analysis . . . . . AC sweep analysis results . . . . . . . . . . . . . . . . Finding out more about AC sweep and noise analysis Parametric analysis . . . . . . . . . . . . . . . . . . . . . . . Setting up and running the parametric analysis . . . . Analyzing waveform families . . . . . . . . . . . . . . Finding out more about parametric analysis . . . . . . Performance analysis . . . . . . . . . . . . . . . . . . . . . Finding out more about performance analysis . . . . . iv Contents Part two Chapter 3 Design entry Preparing a design for simulation 55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 . 56 . 56 . 57 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 58 59 60 61 61 62 64 65 66 67 67 67 69 69 74 74 75 75 76 77 79 79 79 81 81 82 82 83 83 83 84 84 v Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . Checklist for simulation setup . . . . . . . . . . . . . . . . . . . . . Typical simulation setup steps . . . . . . . . . . . . . . . . . . . Advanced design entry and simulation setup steps . . . . . . . When netlisting fails or the simulation does not start . . . . . . . . . . . . . . . . . . . . . . . . Things to check in your design . . . . . . . . . . . . . . . . Things to check in your system configuration . . . . . . . . Using parts that you can simulate . . . . . . . . . . . . . . . . . . . Vendor-supplied parts . . . . . . . . . . . . . . . . . . . . . . . Part naming conventions . . . . . . . . . . . . . . . . . . . . Finding the part that you want . . . . . . . . . . . . . . . . Passive parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Breakout parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . Behavioral parts . . . . . . . . . . . . . . . . . . . . . . . . . . . Using global parameters and expressions for values . . . . . . . . Global parameters . . . . . . . . . . . . . . . . . . . . . . . . . . Declaring and using a global parameter . . . . . . . . . . . Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Specifying expressions . . . . . . . . . . . . . . . . . . . . . Defining power supplies . . . . . . . . . . . . . . . . . . . . . . . . For the analog portion of your circuit . . . . . . . . . . . . . . . Defining stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analog stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using VSTIM and ISTIM . . . . . . . . . . . . . . . . . . . . If you want to specify multiple stimulus types . . . . . . . Things to watch for . . . . . . . . . . . . . . . . . . . . . . . . . . . Unmodeled parts . . . . . . . . . . . . . . . . . . . . . . . . . . Do this if the part in question is from the OrCAD libraries Check for this if the part in question is custom-built . . . . Unconfigured model, stimulus, or include files . . . . . . . . . Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . Unmodeled pins . . . . . . . . . . . . . . . . . . . . . . . . . . . Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . Missing ground . . . . . . . . . . . . . . . . . . . . . . . . . . . Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . Missing DC path to ground . . . . . . . . . . . . . . . . . . . . Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . Contents Chapter 4 Creating and editing models 85 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 87 87 87 88 88 89 89 90 90 91 92 93 94 95 96 96 97 97 99 99 100 100 101 101 102 102 103 104 104 105 105 107 108 109 110 110 111 Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . What are models? . . . . . . . . . . . . . . . . . . . . . . . . . Models defined as model parameter sets . . . . . . . . Models defined as subcircuit netlists . . . . . . . . . . How are models organized? . . . . . . . . . . . . . . . . . . . Model libraries . . . . . . . . . . . . . . . . . . . . . . . . . Model library configuration . . . . . . . . . . . . . . . . . Global vs. design models and libraries . . . . . . . . . . . Nested model libraries . . . . . . . . . . . . . . . . . . . . OrCAD-provided models . . . . . . . . . . . . . . . . . . . Tools to create and edit models . . . . . . . . . . . . . . . . . . Ways to create and edit models . . . . . . . . . . . . . . . . . . Using the Model Editor to edit models . . . . . . . . . . . . . . . . . . . . . . . . . Ways to use the Model Editor . . . . . . . . . . . . . . . . Model Editor-supported device types . . . . . . . . . . . . Ways To Characterize Models . . . . . . . . . . . . . . . . Creating models from data sheet information . . . . . Analyzing the effect of model parameters on device characteristics . . . . . . . . . . . . . How to fit models . . . . . . . . . . . . . . . . . . . . . . . Running the Model Editor alone . . . . . . . . . . . . . . . Starting the Model Editor . . . . . . . . . . . . . . . . . Enabling and disabling automatic part creation . . . . Saving global models (and parts) . . . . . . . . . . . . Running the Model Editor from the schematic page editor What is an instance model? . . . . . . . . . . . . . . . . Starting the Model Editor . . . . . . . . . . . . . . . . . Saving design models . . . . . . . . . . . . . . . . . . . What happens if you don't save the instance model . . The Model Editor tutorial . . . . . . . . . . . . . . . . . . . Creating the half-wave rectifier design . . . . . . . . . Using the Model Editor to edit the D1 diode model . . Entering data sheet information . . . . . . . . . . . . . Extracting model parameters . . . . . . . . . . . . . . . Adding curves for more than one temperature . . . . Completing the model definition . . . . . . . . . . . . Editing model text . . . . . . . . . . . . . . . . . . . . . . . . . Editing .MODEL definitions . . . . . . . . . . . . . . . Editing .SUBCKT definitions . . . . . . . . . . . . . . . vi Contents Changing the model name . . . . . . . . . . . . . . . . . Starting the Model Editor from the schematic page editor in Capture . . . . . What is an instance model? . . . . . . . . . . . . . . . . Starting the Model Editor . . . . . . . . . . . . . . . . . Saving design models . . . . . . . . . . . . . . . . . . . Example: editing a Q2N2222 instance model . . . . . . . . . Starting the Model Editor . . . . . . . . . . . . . . . . . Editing the Q2N2222-X model instance . . . . . . . . . Saving the edits and updating the schematic . . . . . . Using the Create Subcircuit command . . . . . . . . . . . . . . Changing the model reference to an existing model definition . Reusing instance models . . . . . . . . . . . . . . . . . . . . . . Reusing instance models in the same schematic . . . . . . . Making instance models available to all designs . . . . . . Configuring model libraries . . . . . . . . . . . . . . . . . . . . The Libraries and Include Files tabs . . . . . . . . . . . . . . How PSpice uses model libraries . . . . . . . . . . . . . . . Search order . . . . . . . . . ...