Orcad PSPICE User Manual

OrCAD PSpice

User’s Guide

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 (503) 671-9400

Corporate offices (503) 671-9500 OrCAD Japan K.K. 81-45-621-1911 OrCAD UK Ltd. 44-1256-381-400 Fax (503) 671-9501 General email info@orcad.com Technical Support email techsupport@orcad.com World Wide Web http://www.orcad.com OrCAD Design Network (ODN) http://www.orcad.com/odn

9300 SW Nimbus Ave. Beaverton, OR 97008 USA

Before you begin xxiii

Welcome to OrCAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii

OrCAD PSpice overview . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv

How to use this guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv

Typographical conventions . . . . . . . . . . . . . . . . . . . . . . . xxv

Related documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvi

Online Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii

If you have the demo CD-ROM . . . . . . . . . . . . . . . . . . . . xxviii

OrCAD demo CD-ROM . . . . . . . . . . . . . . . . . . . . . . xxviii

What’s New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxix

Part one Simulation primer

Things you need to know 1Chapter 1

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

What is PSpice? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Analyses you can run with PSpice . . . . . . . . . . . . . . . . . . . . . . . 3

Basic analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

DC sweep & other DC calculations . . . . . . . . . . . . . . . . . . 3

AC sweep and noise . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Transient and Fourier . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Advanced multi-run analyses . . . . . . . . . . . . . . . . . . . . . . . 6

Parametric and temperature . . . . . . . . . . . . . . . . . . . . . . 6

Monte Carlo and sensitivity/worst-case . . . . . . . . . . . . . . . 7

Analyzing waveforms with PSpice . . . . . . . . . . . . . . . . . . . . . . 8

What is waveform analysis? . . . . . . . . . . . . . . . . . . . . . . . . 8

Using PSpice with other OrCAD programs . . . . . . . . . . . . . . . . . . 9

Using Capture to prepare for simulation . . . . . . . . . . . . . . . . 9

What is the Stimulus Editor? . . . . . . . . . . . . . . . . . . . . . . . 9

What is the Model Editor? . . . . . . . . . . . . . . . . . . . . . . . . . 10

Contents

Files needed for simulation . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Files that Capture generates . . . . . . . . . . . . . . . . . . . . . . . 10

Netlist file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Circuit file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Other files that you can configure for simulation . . . . . . . . . . . 11

Model library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Stimulus file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Include file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Configuring model library, stimulus, and

include files . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Files that PSpice generates . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Waveform data file . . . . . . . . . . . . . . . . . . . . . . . . . . 14

PSpice output file . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Simulation examples 15Chapter 2

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Example circuit creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Finding out more about setting up your design . . . . . . . . . . . . 21

Running PSpice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Performing a bias point analysis . . . . . . . . . . . . . . . . . . . . . 22

Using the simulation output file . . . . . . . . . . . . . . . . . . . . . 24

Finding out more about bias point calculations . . . . . . . . . . . . 25

DC sweep analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Setting up and running a DC sweep analysis . . . . . . . . . . . . . . 26

Displaying DC analysis results . . . . . . . . . . . . . . . . . . . . . . 28

Finding out more about DC sweep analysis . . . . . . . . . . . . . . 31

Transient analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Finding out more about transient analysis . . . . . . . . . . . . . . . 36

AC sweep analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Setting up and running an AC sweep analysis . . . . . . . . . . . . . 37

AC sweep analysis results . . . . . . . . . . . . . . . . . . . . . . . . 39

Finding out more about AC sweep and noise analysis . . . . . . . . 41

Parametric analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Setting up and running the parametric analysis . . . . . . . . . . . . 43

Analyzing waveform families . . . . . . . . . . . . . . . . . . . . . . 45

Finding out more about parametric analysis . . . . . . . . . . . . . . 48

Performance analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Finding out more about performance analysis . . . . . . . . . . . . . 51

Part two Design entry

Preparing a design for simulation 55Chapter 3

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Checklist for simulation setup . . . . . . . . . . . . . . . . . . . . . . . . . 56

Typical simulation setup steps . . . . . . . . . . . . . . . . . . . . . . . 56

Advanced design entry and simulation setup steps . . . . . . . . . . . 57

When netlisting fails or the simulation

does not start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Things to check in your design . . . . . . . . . . . . . . . . . . . . 58

Things to check in your system configuration . . . . . . . . . . . . 59

Using parts that you can simulate . . . . . . . . . . . . . . . . . . . . . . . 60

Vendor-supplied parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Part naming conventions . . . . . . . . . . . . . . . . . . . . . . . . 61

Finding the part that you want . . . . . . . . . . . . . . . . . . . . 62

Passive parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Breakout parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Behavioral parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Using global parameters and expressions for values . . . . . . . . . . . . 67

Global parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Declaring and using a global parameter . . . . . . . . . . . . . . . 67

Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Specifying expressions . . . . . . . . . . . . . . . . . . . . . . . . . 69

Defining power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

For the analog portion of your circuit . . . . . . . . . . . . . . . . . . . 74

Defining stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Analog stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Using VSTIM and ISTIM . . . . . . . . . . . . . . . . . . . . . . . . 76

If you want to specify multiple stimulus types . . . . . . . . . . . 77

Things to watch for . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Unmodeled parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Do this if the part in question is from the OrCAD libraries . . . . 79

Check for this if the part in question is custom-built . . . . . . . . 81

Unconfigured model, stimulus, or include files . . . . . . . . . . . . . 81

Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Unmodeled pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Missing ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Missing DC path to ground . . . . . . . . . . . . . . . . . . . . . . . . 84

Check for this . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Contents

Creating and editing models 85Chapter 4

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

What are models? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Models defined as model parameter sets . . . . . . . . . . . . . . 87

Models defined as subcircuit netlists . . . . . . . . . . . . . . . . 87

How are models organized? . . . . . . . . . . . . . . . . . . . . . . . . . 88

Model libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Model library configuration . . . . . . . . . . . . . . . . . . . . . . . 89

Global vs. design models and libraries . . . . . . . . . . . . . . . . . 89

Nested model libraries . . . . . . . . . . . . . . . . . . . . . . . . . . 90

OrCAD-provided models . . . . . . . . . . . . . . . . . . . . . . . . . 90

Tools to create and edit models . . . . . . . . . . . . . . . . . . . . . . . . 91

Ways to create and edit models . . . . . . . . . . . . . . . . . . . . . . . . 92

Using the Model Editor to

edit models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Ways to use the Model Editor . . . . . . . . . . . . . . . . . . . . . . 94

Model Editor-supported device types . . . . . . . . . . . . . . . . . . 95

Ways To Characterize Models . . . . . . . . . . . . . . . . . . . . . . 96

Creating models from data sheet information . . . . . . . . . . . 96

Analyzing the effect of model parameters

on device characteristics . . . . . . . . . . . . . . . . . . . 97

How to fit models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Running the Model Editor alone . . . . . . . . . . . . . . . . . . . . . 99

Starting the Model Editor . . . . . . . . . . . . . . . . . . . . . . . 99

Enabling and disabling automatic part creation . . . . . . . . . . 100

Saving global models (and parts) . . . . . . . . . . . . . . . . . . 100

Running the Model Editor from the schematic page editor . . . . . . 101

What is an instance model? . . . . . . . . . . . . . . . . . . . . . . 101

Starting the Model Editor . . . . . . . . . . . . . . . . . . . . . . . 102

Saving design models . . . . . . . . . . . . . . . . . . . . . . . . . 102

What happens if you don’t save the instance model . . . . . . . . 103

The Model Editor tutorial . . . . . . . . . . . . . . . . . . . . . . . . . 104

Creating the half-wave rectifier design . . . . . . . . . . . . . . . 104

Using the Model Editor to edit the D1 diode model . . . . . . . . 105

Entering data sheet information . . . . . . . . . . . . . . . . . . . 105

Extracting model parameters . . . . . . . . . . . . . . . . . . . . . 107

Adding curves for more than one temperature . . . . . . . . . . 108

Completing the model definition . . . . . . . . . . . . . . . . . . 109

Editing model text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Editing .MODEL definitions . . . . . . . . . . . . . . . . . . . . . 110

Editing .SUBCKT definitions . . . . . . . . . . . . . . . . . . . . . 111

Contents

Changing the model name . . . . . . . . . . . . . . . . . . . . . . 111

Starting the Model Editor

from the schematic page editor in Capture . . . . . . . . . . 111

What is an instance model? . . . . . . . . . . . . . . . . . . . . . 112

Starting the Model Editor . . . . . . . . . . . . . . . . . . . . . . 112

Saving design models . . . . . . . . . . . . . . . . . . . . . . . . 113

Example: editing a Q2N2222 instance model . . . . . . . . . . . . . . 114

Starting the Model Editor . . . . . . . . . . . . . . . . . . . . . . 114

Editing the Q2N2222-X model instance . . . . . . . . . . . . . . 114

Saving the edits and updating the schematic . . . . . . . . . . . 115

Using the Create Subcircuit command . . . . . . . . . . . . . . . . . . . 115

Changing the model reference to an existing model definition . . . . . . 117

Reusing instance models . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Reusing instance models in the same schematic . . . . . . . . . . . . 118

Making instance models available to all designs . . . . . . . . . . . 119

Configuring model libraries . . . . . . . . . . . . . . . . . . . . . . . . . 120

The Libraries and Include Files tabs . . . . . . . . . . . . . . . . . . . 120

How PSpice uses model libraries . . . . . . . . . . . . . . . . . . . . 121

Search order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Handling duplicate model names . . . . . . . . . . . . . . . . . . 122

Adding model libraries to the configuration . . . . . . . . . . . . . . 122

Changing design and global scope . . . . . . . . . . . . . . . . . . . 123

Changing model library search order . . . . . . . . . . . . . . . . . . 124

Changing the library search path . . . . . . . . . . . . . . . . . . . . 125

Creating parts for models 127Chapter 5

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

What’s different about parts used for simulation? . . . . . . . . . . . . . 129

Ways to create parts

for models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Preparing your models for part creation . . . . . . . . . . . . . . . . . . 130

Using the Model Editor to create parts . . . . . . . . . . . . . . . . . . . 131

Starting the Model Editor . . . . . . . . . . . . . . . . . . . . . . . . . 131

Setting up automatic part creation . . . . . . . . . . . . . . . . . . . 132

Basing new parts on a custom set of parts . . . . . . . . . . . . . . . . . 133

Editing part graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

How Capture places parts . . . . . . . . . . . . . . . . . . . . . . . . 135

Defining grid spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Grid spacing for graphics . . . . . . . . . . . . . . . . . . . . . . 136

Grid spacing for pins . . . . . . . . . . . . . . . . . . . . . . . . . 136

Attaching models to parts . . . . . . . . . . . . . . . . . . . . . . . . . . 138

vii

Contents

MODEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Defining part properties needed for simulation . . . . . . . . . . . . . . 139

PSPICETEMPLATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

PSPICETEMPLATE syntax . . . . . . . . . . . . . . . . . . . . . . 140

PSPICETEMPLATE examples . . . . . . . . . . . . . . . . . . . . 143

Analog behavioral modeling 147Chapter 6

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

Overview of analog behavioral modeling . . . . . . . . . . . . . . . . . . 148

The ABM.OLB part library file . . . . . . . . . . . . . . . . . . . . . . . . 149

Placing and specifying ABM parts . . . . . . . . . . . . . . . . . . . . . . 150

Net names and device names in ABM expressions . . . . . . . . . . 150

Forcing the use of a global definition . . . . . . . . . . . . . . . . . . 151

ABM part templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

Control system parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Basic components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Limiters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

Chebyshev filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Integrator and differentiator . . . . . . . . . . . . . . . . . . . . . . . 160

Table look-up parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

Laplace transform part . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Math functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

ABM expression parts . . . . . . . . . . . . . . . . . . . . . . . . . . 168

An instantaneous device example: modeling a triode . . . . . . . . . 171

PSpice-equivalent parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

Implementation of PSpice -equivalent parts . . . . . . . . . . . . . . 175

Modeling mathematical or instantaneous relationships . . . . . . . . 176

EVALUE and GVALUE parts . . . . . . . . . . . . . . . . . . . . 176

EMULT, GMULT, ESUM, and GSUM . . . . . . . . . . . . . . . . 178

Lookup tables (ETABLE and GTABLE) . . . . . . . . . . . . . . . . . 179

Frequency-domain device models . . . . . . . . . . . . . . . . . . . . 181

Laplace transforms (LAPLACE) . . . . . . . . . . . . . . . . . . . . . 181

Frequency response tables (EFREQ and GFREQ) . . . . . . . . . . . 183

Cautions and recommendations for simulation and analysis . . . . . . . 186

Instantaneous device modeling . . . . . . . . . . . . . . . . . . . . . 186

Frequency-domain parts . . . . . . . . . . . . . . . . . . . . . . . . . 187

Laplace transforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Non-causality and Laplace transforms . . . . . . . . . . . . . . . 188

Chebyshev filters . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Frequency tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Trading off computer resources for accuracy . . . . . . . . . . . . . . 191

viii

Basic controlled sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Creating custom ABM parts . . . . . . . . . . . . . . . . . . . . . . . 192

Part three Setting Up and Running Analyses

Setting up analyses and starting simulation 195Chapter 7

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

Analysis types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Setting up analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Execution order for standard analyses . . . . . . . . . . . . . . . . . 198

Output variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

Modifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

Starting a simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

Starting a simulation from Capture . . . . . . . . . . . . . . . . . . . 206

Starting a simulation outside of Capture . . . . . . . . . . . . . . . . 207

Setting up batch simulations . . . . . . . . . . . . . . . . . . . . . . . 207

Multiple simulation setups within one circuit file . . . . . . . . . 207

Running simulations with multiple circuit files . . . . . . . . . . 208

The PSpice simulation window . . . . . . . . . . . . . . . . . . . . . 208

Contents

DC analyses 213Chapter 8

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

DC Sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Minimum requirements to run a DC sweep analysis . . . . . . . . . 214

Overview of DC sweep . . . . . . . . . . . . . . . . . . . . . . . . . . 216

Setting up a DC stimulus . . . . . . . . . . . . . . . . . . . . . . . . . 218

Nested DC sweeps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

Curve families for DC sweeps . . . . . . . . . . . . . . . . . . . . . . 221

Bias point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Minimum requirements to run a bias point analysis . . . . . . . . . 223

Overview of bias point . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Small-signal DC transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

Minimum requirements to run a small-signal DC transfer analysis . 225

Overview of small-signal DC transfer . . . . . . . . . . . . . . . . . . 226

DC sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

Minimum requirements to run a DC sensitivity analysis . . . . . . . 228

Overview of DC sensitivity . . . . . . . . . . . . . . . . . . . . . . . . 229

AC analyses 231Chapter 9

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

Contents

AC sweep analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

Setting up and running an AC sweep . . . . . . . . . . . . . . . . . . 232

What is AC sweep? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

Setting up an AC stimulus . . . . . . . . . . . . . . . . . . . . . . . . 233

Setting up an AC analysis . . . . . . . . . . . . . . . . . . . . . . . . . 235

AC sweep setup in example.opj . . . . . . . . . . . . . . . . . . . . . 237

How PSpice treats nonlinear devices . . . . . . . . . . . . . . . . . . 239

What’s required to transform a device into a linear circuit . . . . 239

What PSpice does . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

Example: nonlinear behavioral modeling block . . . . . . . . . . 239

Noise analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

Setting up and running a noise analysis . . . . . . . . . . . . . . . . . 241

What is noise analysis? . . . . . . . . . . . . . . . . . . . . . . . . . . 242

How PSpice calculates total output

and input noise . . . . . . . . . . . . . . . . . . . . . . . . 242

Setting up a noise analysis . . . . . . . . . . . . . . . . . . . . . . . . 243

Analyzing Noise in the Probe window . . . . . . . . . . . . . . . . . 245

About noise units . . . . . . . . . . . . . . . . . . . . . . . . . . . 246

Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246

Transient analysis 249Chapter 10

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

Overview of transient analysis . . . . . . . . . . . . . . . . . . . . . . . . 250

Minimum requirements to run a transient analysis . . . . . . . . . . 250

Minimum circuit design requirements . . . . . . . . . . . . . . . 250

Minimum program setup requirements . . . . . . . . . . . . . . 250

Defining a time-based stimulus . . . . . . . . . . . . . . . . . . . . . . . 252

Overview of stimulus generation . . . . . . . . . . . . . . . . . . . . 252

The Stimulus Editor utility . . . . . . . . . . . . . . . . . . . . . . . . . . 253

Stimulus files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253

Configuring stimulus files . . . . . . . . . . . . . . . . . . . . . . . . 254

Starting the Stimulus Editor . . . . . . . . . . . . . . . . . . . . . . . 254

Defining stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256

Example: piecewise linear stimulus . . . . . . . . . . . . . . . . . 256

Example: sine wave sweep . . . . . . . . . . . . . . . . . . . . . . 257

Creating new stimulus symbols . . . . . . . . . . . . . . . . . . . . . 259

Editing a stimulus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260

To edit an existing stimulus . . . . . . . . . . . . . . . . . . . . . 260

To edit a PWL stimulus . . . . . . . . . . . . . . . . . . . . . . . . 260

To select a time and value scale factor for PWL stimuli . . . . . . 260

Deleting and removing traces . . . . . . . . . . . . . . . . . . . . . . 261

Contents

Manual stimulus configuration . . . . . . . . . . . . . . . . . . . . . 261

To manually configure a stimulus . . . . . . . . . . . . . . . . . 261

Transient (time) response . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

Internal time steps in transient analyses . . . . . . . . . . . . . . . . . . 265

Switching circuits in transient analyses . . . . . . . . . . . . . . . . . . . 266

Plotting hysteresis curves . . . . . . . . . . . . . . . . . . . . . . . . . . . 266

Fourier components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268

Parametric and temperature analysis 271Chapter 11

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

Parametric analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

Minimum requirements to run a parametric analysis . . . . . . . . . 272

Overview of parametric analysis . . . . . . . . . . . . . . . . . . . . 273

RLC filter example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

Entering the design . . . . . . . . . . . . . . . . . . . . . . . . . . 274

Running the simulation . . . . . . . . . . . . . . . . . . . . . . . 275

Using performance analysis to plot overshoot and rise time . . . 275

Example: frequency response vs. arbitrary parameter . . . . . . . . 278

Setting up the circuit . . . . . . . . . . . . . . . . . . . . . . . . . 278

Temperature analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

Minimum requirements to run a temperature analysis . . . . . . . . 281

Overview of temperature analysis . . . . . . . . . . . . . . . . . . . . 282

Monte Carlo and sensitivity/worst-case analyses 283Chapter 12

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283

Statistical analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284

Overview of statistical analyses . . . . . . . . . . . . . . . . . . . . . 284

Output control for statistical analyses . . . . . . . . . . . . . . . . . . 285

Model parameter values reports . . . . . . . . . . . . . . . . . . . . . 285

Waveform reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286

Collating functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

Temperature considerations in statistical analyses . . . . . . . . . . 288

Monte Carlo analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

Reading the summary report . . . . . . . . . . . . . . . . . . . . 291

Example: Monte Carlo analysis of a pressure sensor . . . . . . . . . 293

Drawing the schematic . . . . . . . . . . . . . . . . . . . . . . . . 293

Defining part values . . . . . . . . . . . . . . . . . . . . . . . . . 294

Setting up the parameters . . . . . . . . . . . . . . . . . . . . . . 295

Using resistors with models . . . . . . . . . . . . . . . . . . . . . 296

Saving the design . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

Defining tolerances for the resistor models . . . . . . . . . . . . 297

Contents

Setting up the analyses . . . . . . . . . . . . . . . . . . . . . . . . 299

Running the analysis and viewing the results . . . . . . . . . . . 300

Monte Carlo Histograms . . . . . . . . . . . . . . . . . . . . . . . . . 301

Chebyshev filter example . . . . . . . . . . . . . . . . . . . . . . . 301

Creating models for Monte Carlo analysis . . . . . . . . . . . . . 302

Setting up the analysis . . . . . . . . . . . . . . . . . . . . . . . . 302

Creating histograms . . . . . . . . . . . . . . . . . . . . . . . . . . 303

Worst-case analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306

Overview of worst-case analysis . . . . . . . . . . . . . . . . . . . . . 306

Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307

Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307

Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308

Caution: An important condition for

correct worst-case analysis . . . . . . . . . . . . . . . . . . 308

Worst-case analysis example . . . . . . . . . . . . . . . . . . . . . . . 309

Tips and other useful information . . . . . . . . . . . . . . . . . . . . 313

VARY BOTH, VARY DEV, and VARY LOT . . . . . . . . . . . . 313

Gaussian distributions . . . . . . . . . . . . . . . . . . . . . . . . 314

YMAX collating function . . . . . . . . . . . . . . . . . . . . . . . 314

RELTOL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Sensitivity analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Manual optimization . . . . . . . . . . . . . . . . . . . . . . . . . 314

Monte Carlo analysis . . . . . . . . . . . . . . . . . . . . . . . . . 315

Part four Viewing results

Analyzing waveforms 319Chapter 13

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

Overview of waveform analysis . . . . . . . . . . . . . . . . . . . . . . . 320

Elements of a plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

Elements of a Probe window . . . . . . . . . . . . . . . . . . . . . . . 322

Managing multiple Probe windows . . . . . . . . . . . . . . . . . . . 323

Printing multiple windows . . . . . . . . . . . . . . . . . . . . . . 323

Setting up waveform analysis . . . . . . . . . . . . . . . . . . . . . . . . . 324

Setting up colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

Editing display and print colors in the PSPICE.INI file . . . . . . 324

Configuring trace color schemes . . . . . . . . . . . . . . . . . . . 326

Viewing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Setting up waveform display from Capture . . . . . . . . . . . . . . 327

Viewing waveforms while simulating . . . . . . . . . . . . . . . . . . 328

Configuring update intervals . . . . . . . . . . . . . . . . . . . . 329

xii

Contents

Interacting with waveform analysis during simulation . . . . . 329

Pausing a simulation and viewing waveforms . . . . . . . . . . 330

Using schematic page markers to add traces . . . . . . . . . . . . . . 331

Limiting waveform data file size . . . . . . . . . . . . . . . . . . . . 334

Limiting file size using markers . . . . . . . . . . . . . . . . . . . 334

Limiting file size by excluding intern al subcircuit data . . . . . . 336

Limiting file size by suppressing the first part

of simulation output . . . . . . . . . . . . . . . . . . . . . 336

Using simulation data from multiple files . . . . . . . . . . . . . . . 337

Appending waveform data files . . . . . . . . . . . . . . . . . . . 337

Adding traces from specific loaded waveform data files . . . . . 338

Saving simulation results in ASCII format . . . . . . . . . . . . . . . 339

Analog example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341

Running the simulation . . . . . . . . . . . . . . . . . . . . . . . 341

Displaying voltages on nets . . . . . . . . . . . . . . . . . . . . . 343

User interface features for waveform analysis . . . . . . . . . . . . . . . 344

Zoom regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344

Scrolling traces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

Modifying trace expressions and labels . . . . . . . . . . . . . . . . . 346

Moving and copying trace names and expressions . . . . . . . . . . 347

Copying and moving labels . . . . . . . . . . . . . . . . . . . . . . . 348

Tabulating trace data values . . . . . . . . . . . . . . . . . . . . . . . 349

Using cursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350

Displaying cursors . . . . . . . . . . . . . . . . . . . . . . . . . . 350

Moving cursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351

Example: using cursors . . . . . . . . . . . . . . . . . . . . . . . . 352

Tracking simulation messages . . . . . . . . . . . . . . . . . . . . . . . . 354

Message tracking from the message summary . . . . . . . . . . . . . 354

The Simulation Message Summary dialog box . . . . . . . . . . 354

Persistent hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . 355

Message tracking from the waveform . . . . . . . . . . . . . . . . . . 356

Trace expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356

Basic output variable form . . . . . . . . . . . . . . . . . . . . . . . . 357

Output variable form for device terminals . . . . . . . . . . . . . . . 358

Analog trace expressions . . . . . . . . . . . . . . . . . . . . . . . . . 364

Trace expression aliases . . . . . . . . . . . . . . . . . . . . . . . 364

Arithmetic functions . . . . . . . . . . . . . . . . . . . . . . . . . 364

Rules for numeric values suffixes . . . . . . . . . . . . . . . . . . 365

Other output opti ons 367Chapter 14

Chapter overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367

xiii

Contents

Viewing analog results in the PSpice window . . . . . . . . . . . . . . . 368

Writing additional results to the PSpice output file . . . . . . . . . . . . 369

Generating plots of voltage and current values . . . . . . . . . . . . 369

Generating tables of voltage and current values . . . . . . . . . . . . 370

Setting initial state 373Appendix A

Appendix overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

Save and load bias point . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374

Save bias point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374

Load bias point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376

Setting initial conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378

Convergence and “time step too small errors” 379Appendix B

Appendix overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380

Newton-Raphson requirements . . . . . . . . . . . . . . . . . . . . . 380

Is there a solution? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381

Are the Equations Continuous? . . . . . . . . . . . . . . . . . . . . . 382

Are the derivatives correct? . . . . . . . . . . . . . . . . . . . . . 382

Is the initial approximation close enough? . . . . . . . . . . . . . . . 383

Bias point and DC sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

Semiconductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

Behavioral modeling expressions . . . . . . . . . . . . . . . . . . . . 387

Transient analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388

Skipping the bias point . . . . . . . . . . . . . . . . . . . . . . . . . . 389

The dynamic range of TIME . . . . . . . . . . . . . . . . . . . . . . . 389

Failure at the first time step . . . . . . . . . . . . . . . . . . . . . . . . 390

Parasitic capacitances . . . . . . . . . . . . . . . . . . . . . . . . . . . 391

Inductors and transformers . . . . . . . . . . . . . . . . . . . . . . . . 391

Bipolar transistors substrate junction . . . . . . . . . . . . . . . . . . 392

Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393

xiv

Index 395

Figures

Figure 1 User-configurable data files that PSpice reads . . . . . . . . . . . . . . . . 11

Figure 2 Diode clipper circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 3 Connection points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 4 PSpice simulation output window. . . . . . . . . . . . . . . . . . . . . . . 22

Figure 5 Simulation output file. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 6 DC sweep analysis settings. . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 7 Probe window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 8 Clipper circuit with voltage marker on net Out. . . . . . . . . . . . . . . . 29

Figure 9 Voltage at In, Mid, and Out. . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 11 Trace legend with cursors activated. . . . . . . . . . . . . . . . . . . . . . 30

Figure 12 Trace legend with V(Mid) symbol outlined. . . . . . . . . . . . . . . . . . 30

Figure 13 Voltage difference at V(In) = 4 volts. . . . . . . . . . . . . . . . . . . . . . 31

Figure 14 Diode clipper circuit with a voltage stimulus. . . . . . . . . . . . . . . . . 32

Figure 15 Stimulus Editor window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 16 Transient analysis simulation settings. . . . . . . . . . . . . . . . . . . . . 34

Figure 17 Sinusoidal input and clipped output waveforms. . . . . . . . . . . . . . . 35

Figure 18 Clipper circuit with AC stimulus. . . . . . . . . . . . . . . . . . . . . . . . 37

Figure 19 AC sweep and noise analysis simulation settings. . . . . . . . . . . . . . . 38

Figure 20 dB magnitude curves for “gain” at Mid and Out. . . . . . . . . . . . . . . 40

Figure 21 Bode plot of clipper’s frequency response. . . . . . . . . . . . . . . . . . . 41

Figure 22 Clipper circuit with global parameter Rval. . . . . . . . . . . . . . . . . . 42

Figure 23 Parametric simulation settings. . . . . . . . . . . . . . . . . . . . . . . . . . 44

Ω

Figure 24 Small signal response as R1 is varied from 100

Figure 25 Small signal frequency response at 100 and 10 kΩ input resistance. . . . 47

Figure 26 Performance analysis plots of bandwidth and gain vs. Rval. . . . . . . . . 50

Figure 27 Relationship of the Model Editor to Capture and PSpice . . . . . . . . . . 93

Figure 28 Process and data flow for the Model Editor. . . . . . . . . . . . . . . . . . 96

Figure 29 Model Editor workspace with data for a bipolar transistor. . . . . . . . . 97

Figure 30 Design for a half-wave rectifier. . . . . . . . . . . . . . . . . . . . . . . . 104

Figure 31 Model characteristics and parameter values for DbreakX. . . . . . . . . 105

Figure 32 Assorted device characteristic curves for a diode. . . . . . . . . . . . . . 108

Figure 33 Forward Current device curve at two temperatures. . . . . . . . . . . . 109

to 10 k

Ω . . . . . . . . . . . 45

Figures

Figure 34 Rules for pin callout in subcircuit templates. . . . . . . . . . . . . . . . . 146

Figure 35 LOPASS filter example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Figure 36 HIPASS filter part example. . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Figure 37 BANDPASS filter part example. . . . . . . . . . . . . . . . . . . . . . . . 159

Figure 38 BANDREJ filter part example. . . . . . . . . . . . . . . . . . . . . . . . . 159

Figure 39 FTABLE part example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Figure 40 LAPLACE part example one. . . . . . . . . . . . . . . . . . . . . . . . . . 165

Figure 41 Viewing gain and phase characteristics of a lossy integrator. . . . . . . . 165

Figure 42 LAPLACE part example two. . . . . . . . . . . . . . . . . . . . . . . . . . 165

Figure 43 ABM expression part example one. . . . . . . . . . . . . . . . . . . . . . 169

Figure 44 ABM expression part example two. . . . . . . . . . . . . . . . . . . . . . 169

Figure 45 ABM expression part example three. . . . . . . . . . . . . . . . . . . . . . 170

Figure 46 ABM expression part example four. . . . . . . . . . . . . . . . . . . . . . 170

Figure 47 Triode circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Figure 48 Triode subcircuit producing a family of I-V curves. . . . . . . . . . . . . 173

Figure 49 EVALUE part example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Figure 50 GVALUE part example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Figure 51 EMULT part example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Figure 52 GMULT part example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Figure 53 EFREQ part example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Figure 54 Voltage multiplier circuit (mixer). . . . . . . . . . . . . . . . . . . . . . . 186

Figure 55 PSpice simulation window . . . . . . . . . . . . . . . . . . . . . . . . . . 210

Figure 56 Example schematic EXAMPLE.OPJ. . . . . . . . . . . . . . . . . . . . . . 217

Figure 57 Curve family example schematic. . . . . . . . . . . . . . . . . . . . . . . 221

Figure 58 Device curve family. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

Figure 59 Operating point determination for each member of the curve family. . . 222

Figure 60 Circuit diagram for EXAMPLE.OPJ. . . . . . . . . . . . . . . . . . . . . . 237

Figure 61 AC analysis setup for EXAMPLE.OPJ. . . . . . . . . . . . . . . . . . . . . 238

Figure 62 Device and total noise traces for EXAMPLE.DSN. . . . . . . . . . . . . . 247

Figure 63 Transient analysis setup for EXAMPLE.OPJ. . . . . . . . . . . . . . . . . 263

Figure 64 Example schematic EXAMPLE.OPJ. . . . . . . . . . . . . . . . . . . . . . 264

Figure 65 ECL-compatible Schmitt trigger. . . . . . . . . . . . . . . . . . . . . . . . 266

Figure 66 Netlist for Schmitt trigger circuit. . . . . . . . . . . . . . . . . . . . . . . . 267

Figure 67 Hysteresis curve example: Schmitt trigger. . . . . . . . . . . . . . . . . . 268

Figure 68 Passive filter schematic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

Figure 69 Current of L1 when R1 is 1.5 ohms. . . . . . . . . . . . . . . . . . . . . . 276

Figure 70 Rise time and overshoot vs. damping resistance. . . . . . . . . . . . . . . 277

Figure 71 RLC filter example circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . 278

Figure 72 Plot of capacitance versus bias voltage. . . . . . . . . . . . . . . . . . . . 280

Figure 73 Example schematic EXAMPLE.OPJ. . . . . . . . . . . . . . . . . . . . . . 282

Figure 74 Example schematic EXAMPLE.DSN. . . . . . . . . . . . . . . . . . . . . 288

Figure 75 Monte Carlo analysis setup for EXAMPLE.DSN. . . . . . . . . . . . . . . 290

xvi

Figures

Figure 76 Summary of Monte Carlo runs for EXAMPLE.OPJ. . . . . . . . . . . . . 291

Figure 77 Parameter values for Monte Carlo pass three. . . . . . . . . . . . . . . . 292

Figure 78 Pressure sensor circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

Figure 79 Model definition for RMonte1. . . . . . . . . . . . . . . . . . . . . . . . . 298

Figure 80 Pressure sensor circuit with RMonte1 and RTherm model definitions. . 299

Figure 81 Chebyshev filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

Figure 82 1 dB bandwidth histogram. . . . . . . . . . . . . . . . . . . . . . . . . . . 305

Figure 83 Center frequency histogram. . . . . . . . . . . . . . . . . . . . . . . . . . 306

Figure 84 Simple biased BJT amplifier. . . . . . . . . . . . . . . . . . . . . . . . . . 309

Figure 85 Amplifier netlist and circuit file. . . . . . . . . . . . . . . . . . . . . . . . 310

Figure 86 YatX Goal Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

Figure 87 Correct worst-case results. . . . . . . . . . . . . . . . . . . . . . . . . . . 312

Figure 88 Incorrect worst-case results. . . . . . . . . . . . . . . . . . . . . . . . . . 312

Figure 89 Schematic using VARY BOTH. . . . . . . . . . . . . . . . . . . . . . . . . 313

Figure 90 Circuit file using VARY BOTH. . . . . . . . . . . . . . . . . . . . . . . . 313

Figure 91 Analog and digital areas of a plot. . . . . . . . . . . . . . . . . . . . . . . 321

Figure 92 Two Probe windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

Figure 93 Trace legend symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338

Figure 94 Section information message box. . . . . . . . . . . . . . . . . . . . . . . 339

Figure 95 Example schematic EXAMPLE.OPJ. . . . . . . . . . . . . . . . . . . . . . 341

Figure 96 Waveform display for EXAMPLE.DAT. . . . . . . . . . . . . . . . . . . 342

Figure 97 Cursors positioned on a trough and peak of V(1) . . . . . . . . . . . . . 352

Figure 98 Waveform display for a persistent hazard. . . . . . . . . . . . . . . . . . 355

Figure A-1 Setpoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376

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Figures

xviii

Tables

Table 1 DC analysis types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Table 2 AC analysis types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Table 3 Time-based analysis types . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Table 4 Parametric and temperature analysis types . . . . . . . . . . . . . . . . . . 6

Table 5 Statistical analysis types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 2-1 25

Table 10 Association of cursors with mouse buttons. . . . . . . . . . . . . . . . . . 30

Table 2-1 31 Table 2-1 36 Table 2-2 41 Table 2-3 48 Table 2-4 51 Table 5 58 Table 6 59

Table 7 Passive parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table 8 Breakout parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Table 9 Operators in expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Table 10 Function s in arithmetic expressions . . . . . . . . . . . . . . . . . . . . . . 71

Table 11 System variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Table 12 74 Table 13 75 Table 14 77 Table 15 78 Table 16 80

Table 17 Models supported in the Model Editor . . . . . . . . . . . . . . . . . . . 95

Table 1 Sample diode data sheet values . . . . . . . . . . . . . . . . . . . . . . . 106

Table 2 Part names for custom part generation. . . . . . . . . . . . . . . . . . . . 133

Table 3 139 Table 4 141 Table 5 142 Table 6 145

Table 7 Control system parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Tables

Table 1 ABM math function parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

Table 2 ABM expression parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

Table 1 PSpice -equivalent parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

Table 1 Basic controlled sources in ANALOG.OLB . . . . . . . . . . . . . . . . . 192

Table 2 Classes of PSpice analyses . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Table 3 Execution order for standard analyses . . . . . . . . . . . . . . . . . . . . 198

Table 4 PSpice output variable formats . . . . . . . . . . . . . . . . . . . . . . . 201

Table 5 Element definitions for 2-terminal devices . . . . . . . . . . . . . . . . . 202

Table 6 Element definitions for 3- or 4-terminal devices . . . . . . . . . . . . . . 203

Table 7 Element definitions for transmission line devices . . . . . . . . . . . . . 204

Table 8 Element definitions for AC analysis specific elements . . . . . . . . . . 205

Table 9 DC sweep circuit design requirements . . . . . . . . . . . . . . . . . . . 214

Table 10 218 Table 11 218 Table 12 219

Table 1 Curve family example setup . . . . . . . . . . . . . . . . . . . . . . . . . 221

Table 2 233 Table 3 233 Table 4 234 Table 5 234 Table 6 236 Table 7 242 Table 8 244 Table 9 246

Table 10 Stimulus symbols for time-based input signals . . . . . . . . . . . . . . 252

Table 1 Parametric analysis circuit design requir ements . . . . . . . . . . . . . . 272

Table 1 Collating functions used in statistical analyses . . . . . . . . . . . . . . . 287

Table 1 294 Table 2 295 Table 3 300

Table 1 Default waveform viewing colors. . . . . . . . . . . . . . . . . . . . . . . 325

Table 2 326 Table 3 328 Table 4 330 Table 5 332 Table 6 333 Table 1 346

Table 2 Mouse actions for cursor control . . . . . . . . . . . . . . . . . . . . . . . 351

Table 3 Key combinations for cursor control . . . . . . . . . . . . . . . . . . . . 351

Table 4 357 Table 5 358

Table 6 Output variable formats . . . . . . . . . . . . . . . . . . . . . . . . . . . 358

Tables

Table 7 Examples of output variable formats . . . . . . . . . . . . . . . . . . . . 360

Table 8 Output variable AC suffixes . . . . . . . . . . . . . . . . . . . . . . . . . 361

Table 9 Device names for two-terminal device types . . . . . . . . . . . . . . . 361

Table 10 Terminal IDs by three & four-terminal device type . . . . . . . . . . . . 362

Table 11 Noise types by device type . . . . . . . . . . . . . . . . . . . . . . . . . . 363

Table 12 Analog arithmetic functions for trace expressions . . . . . . . . . . . . 364

Table 13 Output units for trace expressions . . . . . . . . . . . . . . . . . . . . . 366

Table 14 369 Table 15 370

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Tables

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Before you begin

Welcome to OrCAD

OrCAD® offers a total solution for your core design tasks: schematic- and VHDL-based design entry; FPGA and CPLD design synthesis; digital, analog, and mixed-signal simulation; and printed circuit board layout. What's more, OrCAD's products are a suite of applications built around an engineer's design flow--not just a collection of independently developed point tools. PSpice is just one element in OrCAD's total solution design flow.

With OrCAD’s products, you’ll spend less time dealing with the details of tool integration, devising workarounds, and manually entering d ata to keep file s in sync. Our products will help you build better products faster, and at lower cost.

Before you begin

OrCAD PSpice overview

OrCAD PSpice simulates analog-only circuits. After you prepare a design for simulation, OrCAD Capture generates a circuit file set. The circuit file set, containing the circuit netlist and analysis commands, is read by PSpice for simulation. PSpice formulates these into meaningful graphical plots, which you can mark for display directly from your schematic page using markers.

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How to use this guide

This guide is designed so you can quickly find the information you need to use PSpice.

This guide assumes that you are familiar with Microsoft Windows (NT or 95), including how to use icons, menus, and dialog boxes. It also assumes you have a basic understanding about how Windows manages applications and files to perform routine tasks, such as starting applications, and openin g and saving your work. If you are new to Windows, please review your Microsoft Windows User’s Guide.

Typographical conventions

Before using PSpice, it is important to understand the terms and typographical conventions used in this documentation.

How to use this guide

This guide generally follows the conventions used in the Microsoft Win dows User’s Guide. Procedures for performing an operation are generally numbered with the following typographical conventions..

Notation Examples Description

C+r

monospace font

Press C+

Type

VAC...

A specific key or key stroke on the keyboard.

. Commands/te xt entered

from the keyborad.

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Before you begin

What’s New

New PSpice interface with integrated waveform analysis functionality Release 9 of PSpice incl udes all

of Probe’s features and adds to them. Included in one screen are tabbed windows for viewing plots, text windows for viewing output files or other text files, and a simulation status and message window. Also included is a new, self-documenting analysis setup dia log for creating simulation profiles (see below). PSpice now provides an editable simulation queue which shows you how many files are currently in line to be simulated. You can edit or re-order the list as needed. And the plotting features have been improved by providing user-controlled grid setti ngs, grid and trace properties (style and color) and metafile format copy and paste functions.

Simulation profiles PSpice Release 9 introduces the

concept of simulation profiles. Each simulation profile refers to one schematic in a design and includes one analysis type (AC, DC, or Transient) with any options (sensitivity, temperature, parametric, Monte Carlo, etc.). You can define as many profiles as you need for your design and you can set up multiple analyses of the same type. Simulation profiles help you keep your analysis results separate, so you can delete one without losing the rest.

To find out more, see Analyzing

waveforms on page -319.

New OrCAD Capture front-end Release 9 integrates

OrCAD Capture as the front-end schematic entry tool for PSpice. Capture provides a professional design entry environment with many advanced capabilities that now work hand-in-hand with PSpice. These include a project manager, a new property editor spreadsheet, right mouse button support, and many other time-saving features.

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Before you begin

To find out more, see Creating and

editing models on page -85.

To find out more, refer to MOSFET devices in the Analog Devices chapter of the online OrCAD PSpice A/D

eference Manual.

New Model Editor interface The Model Editor

(formerly known as Parts) has been improved and modernized for Release 9. It now provides a unified application for editing models either in text form or by modifying their specifications. The Model Editor now also supports Darlington modeling.

EKV version 2.6 MOSFET model The EKV model is a

scalable and compact model built on fundamental physical properties of the device. Use this model to design low-voltage, low-current analog, and mixed analogdigital circuits that use sub-micron technologies.

Version 2.6 models the fo llowing:

• geometrical and process related aspects of the device

(oxide thickness, junction depth, effective channel length and width, and so on)

• effects of doping profile and substrate effects

• weak, moderate, and strong inversion behavior

• mobility effects due to vertical and lateral fields and

carrier velocity saturation

• short-channel effects such as channel-length

modulation, source and drain charge sharing, and the reverse short channel effect

• thermal and flicker noise modeling

• short-distance geometry and bias-dependent device

matching for Monte Carlo analysis

Enhanced model libraries The model libraries

supplied with PSpice Release 9 have been enhanced to include the latest models from various vendors, as well as models for popular optocouplers, Darlingtons, and DAC and ADC devices.

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+ 406 hidden pages

Orcad PSPICE User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

Before you begin

Welcome to OrCAD

OrCAD PSpice overview

How to use this guide

Typographical conventions

Related documentation

Online Help

What’s New