SPICE-Simulation using LTspice IV

1 1 SPICE-Simulation usingLTspice IV Tutorial for successful simulation of electronic circuits with the free full version of LTspice IV (before named SwitcherCAD ), available at Linear Technologies ( ). Version by Gunthard Kraus, Elektronikschule Tettnang, Germany,Guest Lecturer at the DHBW (Duale Hochschule Baden-Wuerttemberg), Friedrichshafen, Germany Email: or ~krausgDecember 15th, 2010 2 Contents Page1. Introduction 5 2. Installation 5 3. Exercises with the included Example Astable Multivibrator 5 using Schematic and simulation 5 Presentation of simulation Results 7 Deleting Curves 8 Changing Curve Colours 9 Changing the simulation Time 10 Changing Current- or Voltage Ranges 12 using Cursors 14

2 Working with one Cursor 14 Working with two Cursors 14 Differential Measurements 15 Current Measurements 16 Changing Part Values 174. Project 1: RC Lowpass Filter 18 Drawing the Circuit Diagram with the Editor 18 Changing Part Values 19 Time Domain simulation : non-repetitive Signals at the Input 20 Step Response 20 Switching ON and OFF 22 Impulse Response 23 Time Domain simulation .

3 using Periodic Signals at the Input 26 Sine Wave (f = 1591 Hz) 26 Square Wave (f = 1591 Hz) 27 Triangle Wave (f = 1591 Hz) Frequency Domain simulation : AC Sweep 29 5. FFT (= Fast Fourier Transform) 316.

4 Project 2: Rectifiers 34 Simple Rectifier without Transformer 34 Important: creating SPICE Model and Symbol for a Transformer 35 The easiest Solution: a simple ideal Transformer Creation of the SPICE Model for a real Two Windings Transformer 35 Creation of the Symbol for a Two Windings Transformer 35 One Pulse Rectifier with Transformer 38 Rectifier with Diode 1N4007 40 Two Pulse Rectifier with Transformer 42

5 7. Project 3: Three Phase AC-system Schematic and simulation 44 Rectifier Bridge for Three Phase AC Systems (= dynamo in a modern car or motorcycle) 45 38. Project 4: U-I-Curves of Parts 47 Resistor 47 Diode 48 NPN Transistor 49 N Channel junction FET 519. Project 5: Transistor Circuits 52 One Stage Amplifier 52 Time Domain simulation 52 Frequency Domain simulation .

6 AC Sweep Two Stage Broadband Amplifier with Feedback 55 Task Circuit Diagram for simulation 55 Time Domain simulation 56 DC Bias 57 Frequency Domain Dimulation: AC Sweep 59 Parametric Sweep 6010.

7 Project 6: OPA Circuits 62 Starting with an Inverting Amplifier 62 Preparing a SPICE Model from the Internet 62 Gainblock for 1kHz to 30 MHz with OPA355 64 simulation using the selfmade OPA355 Subcircuit Model

8 64 Usage of Labels 67 11. Project 7: DC-DC Converters 69 Model for the Power-MOSFET IRFZ44N 69 The Step Up Converter 71 The Flyback Converter 73 The Step Down Converter

9 7512. Project 8: Thyristor Circuits Thyristor Model 77 Switching Resistive Loads 78 Switching Inductive Loads 79 Circuit with Gate-Transformer 80 13. Project 9: Echos on Transmission Lines Transmission Lines -- only two Wires? 81 Echoes 83 simulation of the Example with LTspice 85 Open or Short Circuit at Cable s End 88 Lossy Cables (e.)

10 G. RG58 / 50 ) How can I simulate a RG58 Coaxial Cable? simulation of Cable Loss at 100 MHz Feeding the RG58 Cable Entry with a Pulse Voltage 94 A Short Circuit at RG58 Cables s End 9514. Project 10: S-Parameters 96 Echoes once again, but with more System (= S parameters) Example: 110 MHz Tchebyshev Lowpass Filter (LPF) 99 415.