Cadence OrCAD PCB Designer

Contents
1 Introduction 2
2 One-transistor amplifier: simple analysis 4
3 Schematic capture and simulation 6
4 Preparation for PCB layout 10
5 OrCAD PCB Editor 18
6 Instrumentation amplifier – single-sided board 27
7 Instrumentation amplifier – double-sided board 37
8 A mixed-signal system 40
9 Summary: PCB design flow 45
10 How to correct a layout if you spot an error in the circuit 46
A Where to learn more 47
B Power-user tips and random jottings 49
1 Introduction
This series of exercises introduces you to schematic capture, simulation and PCB layout using
the Cadence OrCAD design suite. This comprises three main applications:
• Capture for the schematic capture of circuits, which enables a circuit to be rapidly drawn
on the screen. It offers great flexibility compared with a traditional pencil and paper
drawing, as design changes can be incorporated and errors corrected quickly and easily.
(On the other hand, it is much faster to develop the outline of a circuit using pencil and
paper.) A netlist, which describes the components and their interconnections, is the link
to PSpice and PCB Editor.
• PSpice to simulate a captured circuit and confirm that it performs as specified. Plots
were produced by a separate application called Probe in the past and I’ll stick to this
name, although it has long been integrated into PSpice.
• PCB Editor (Allegro) for the layout of printed circuit boards. This includes an automatic
router (SPECCTRA) that works out the arrangement of tracks needed to connect your
components on the PCB. The output is a set of files that can be sent to a manufacturer or
the electronics workshop in the Rankine Building.
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