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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

Part
DC Source
2. Draw a Schematic
Part Name Schematic
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

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

Cont..
Place Part (Enter)
Choose the part, i.e., R
3
2
1
Click Analogue

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
Current
Power
Dissipation

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

Graph