Table of Contents Introduction 4 Preface ............................................................................................................ 4 SwitcherCAD III Overview ............................................................................... 6 Hardware Requirements.................................................................................. 7 Software Installation ........................................................................................ 8 License Agreement/Disclaimer........................................................................ 8 Mode of Operation 10 Overview........................................................................................................ 10 Example Circuits............................................................................................ 10 General Purpose Schematic Driven SPICE .................................................. 11 Externally Generated Netlists........................................................................ 12 Efficiency Report ........................................................................................... 13 Schematic Capture 15 Basic Schematic Editing................................................................................ 15 Label a node name........................................................................................ 19 Schematic Colors .......................................................................................... 20 Placing New Components ............................................................................. 21 Programming Keyboard Shortcuts ................................................................ 21 PCB Netlist Extraction ................................................................................... 22 Editing Components ...................................................................................... 23 Edit a Visible Attribute............................................................................. 23 Specialized Component Editors.............................................................. 24 General Attribute Editor .......................................................................... 25 Creating New Symbols .................................................................................. 27 Symbol Editing Overview ........................................................................ 27 Drawing the body .................................................................................... 28 Adding the Pins....................................................................................... 29 Adding Attributes..................................................................................... 29 Attribute Visibility..................................................................................... 31 Hierarchy ....................................................................................................... 32 Hierarchy Overview................................................................................. 32 Rules of Hierarchy................................................................................... 33 Navigating the Hierarchy......................................................................... 34 Waveform Viewer 36 Waveform Viewer Overview .......................................................................... 36 Data Trace Selection ..................................................................................... 36 Zooming......................................................................................................... 41 Waveform Arithmetic ..................................................................................... 41 User-Defined Functions................................................................................. 48 Axis Control ................................................................................................... 49 Plot Panes .....................................................................................................49 Color Control.................................................................................................. 50 Attached Cursors........................................................................................... 51 Save Plot Configurations............................................................................... 55 Fast Access File Format................................................................................ 56 LTspice 57 Introduction.................................................................................................... 58 1 Circuit Description................................................................................... 58 General Structure and Conventions........................................................ 59 Circuit Element Quick Reference............................................................ 62 Dot Commands.............................................................................................. 63 C. Simulator Directives -- Dot Commands............................................. 63 .AC -- Perform an Small Signal AC Analysis Linearized About the DC Operating Point. ....................................................................................................... 64 .BACKANNO -- Annotate the Subcircuit Pin Names to the Port Currents65 .DC -- Perform a DC Source Sweep Analysis ........................................ 65 .END -- End of Netlist.............................................................................. 66 .ENDS -- End of Subcircuit Definition ..................................................... 66 .FOUR -- Compute a Fourier Component after a .TRAN Analysis ......... 66 .FUNC -- User Defined Functions ........................................................... 67 .FERRET -- Download a File Given the URL.......................................... 68 .IC -- Set Initial Conditions ...................................................................... 68 .INCLUDE -- Include Another File........................................................... 69 .LIB -- Include a Library........................................................................... 70 .LOADBIAS -- Load a Previously Solved DC Solution............................ 73 .MEASURE -- Evaluate User-Defined Electrical Quantities.................... 73 .MODEL -- Define a SPICE Model.......................................................... 78 .NET -- Compute Network Parameters in a .AC Analysis...................... 79 .NODESET -- Supply Hints for Initial DC Solution .................................. 80 .NOISE -- Perform a Noise Analysis...................................................... 80 .OP -- Find the DC Operating Point ....................................................... 81 .OPTIONS -- Set Simulator Options ....................................................... 81 .PARAM -- User-Defined Parameters.................................................... 86 .SAVE -- Limit the Quantity of Saved Data. ............................................ 90 .SAVEBIAS -- Save Operating Point to Disk .......................................... 90 .STEP -- Parameter Sweeps................................................................... 91 .SUBCKT -- Define a Subcircuit.............................................................. 92 .TEMP -- Temperature Sweeps .............................................................. 94 .TF -- Find the DC Small Signal Transfer Function................................. 94 .TRAN -- Perform a Nonlinear Transient Analysis .................................. 94 .WAVE -- Write Selected Nodes to a .Wav File. ..................................... 95 Transient Analysis Options............................................................................ 96 .TRAN Modifiers...................................................................................... 96 UIC .......................................................................................................... 96 startup ..................................................................................................... 97 steady...................................................................................................... 97 nodiscard................................................................................................. 98 step ......................................................................................................... 98 Circuit Elements ............................................................................................ 99 A. Special Functions. ............................................................................. 99 B. Arbitrary behavioral voltage or current sources............................... 102 C. Capacitor ......................................................................................... 107 D. Diode ............................................................................................... 110 E. Voltage Dependent Voltage Source ................................................ 113 F. Current Dependent Current Source................................................. 115 G. Voltage Dependent Current Source................................................ 116 H. Current Dependent Voltage Source ................................................ 117 I. Current Source.................................................................................. 118 J. JFET transistor................................................................................. 123 K. Mutual