Personal Simulation Program with Integrated Circuit Emphasis

PSPICE

From SPICE to PSPICE

SPICE: – Engineering design tool for circuit simulation

– SPICE developed in 1970’s by University of California, Berkeley (entirely text-based initially)

PSPICE: – Adapted version of SPICE developed by Microsym in 1984

– A graphical user interface called “Schematics” was added

– Schematics was improved and renamed as “Capture” by Orcad who acquired Microsym later.

Sources of PSpice software

Cadence Orcad PSpice: – Demo versions of the software can be

downloaded free from

http://www.cadence.com/products/orcad/pages/downloads.aspx

– Rooms 3204, 3208, 3203 and 3505 in Nguyen

Engineering Building also have full versions of PSpice installed.

Installation from Cadence Website

• Extract all files from the downloaded folder • Locate and run setup.exe from

….\16.6_OrCAD_Lite_All_Products\Lite Full\Disk1

To open Orcad Capture, go to – All Programs > Cadence > OrCAD 16.6 Lite > OrCAD Capture CIS Lite

Circuit Schematics & Simulation using PSpice

Start a Project

Draw a Schematic

Simulate Circuit

Graph Data

Remember

• Create a new project by using the Analogue or Mixed A/D setting

• Use Pspice subfolder inside the Library folder to add your required libraries

• Every circuit should have a PSpice ground

1. Start a Project

• File > New > Project

2. Draw a Schematic Part Part Name Schematic

DC Source VDC / Source

Ground (ref. voltage) 0 / SOURCE

Resistor R / ANALOG

Capacitor C / ANALOG

Inductor L / ANALOG

Table 1. Summary of commonly used Parts

2.1 Adding Parts to your Circuit

• Go to Place > Part

• To add a library, click on

the icon shown below

Add library icon

Cont..

To add a Resistor in your schematic, use analogue library, and click open

Cont..

Place Part (Enter)

Click Analogue

Choose the part, i.e., R

1

2

3

You can change the value by double clicking here

2.2 Placing a voltage source

2.3 Connect wires

• To connect wires choose Place Wire (W) • Drag cursor from one connection point to another. Clicking on any valid connection will end the wire • Continue connecting the rest of the circuit

2.4 Place Ground

Fig 1. Final Circuit Schematic

Types of Simulation

– AC Sweep • Commonly known as frequency response • Used to simulate a circuit with AC source at different

frequencies

– DC Sweep • Used when it is required to vary the value of a source or a

parameter of the circuit • Can provide a starting value, ending value and increment

size

– Bias Point Analysis (DC) • Used to calculate all node voltages and currents

– Time Domain (Transient) • Used to run the circuit for a specified amount of time

3. Simulate Design

• To get a curve between voltage V and current I, perform the following steps

– Go to PSpice > New simulation profile

Add markers

Voltage Differential Voltage

Power Dissipation Current

4. Graph Data

• After adding Current marker to your schematic, click run and view simulation results to view the graph.

Graph