Download the day before you have lab – 20 pts

Name: _________________________
Lab Instructor:__________________
Lab Date (day/mon/yr): ___/___/____
Lab Day:______ Time: _____-______
ECET297 Lab 2
Schematic Capture cont’d and Layout Introduction
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Objectives
Performance Checks
Prelab
Approach and Results
Analysis and Conclusions
Objectives
The objectives of this lab are:
 Continue to learn the use of a schematic capture tool
 Begin to learn layout of printed circuit boards.
 Verify Exar information relative to the 297 project
 Determine business information about Exar
Instructor Performance/information Checks
_____ 1,
Prelab questions/issues, if any, answered.
_____ 2.
XR2206 Schematic information completed and printed out
Prelab – hand in the last page of this handout by 5PM in the ECET office,
the day before you have lab – 20 pts
1.
297 Project PCB Definition
Based on your Prelab information, discuss your proposed PCB size, mounting, and power
supply sources with your instructor. Consider:
 your proposed use (desktop, pocket size, 196 power supply, etc?),
 the limitations in size that Advanced Circuits has on their $33 specials, and
 decisions considered reasonable by your instructor!
2.
Layout Introduction
This section will introduce you on the techniques to be used in order to begin the creation of a
printed circuit board (PCB) using the Layout capability of PCB Artist.
You will use the op-amp circuit from Lab1 to create a printed board design.
After the board design is defined, and the schematic is transferred to a PCB, the electrical pointto-point connects will be shown in yellow, as defined by your schematic. This pattern of
connections does NOT yet exist in copper, and is known as a “rats nest” of connections.
Using the op-amp circuit, complete Chapter 3 and the beginning of Chapter 4 (stop at
“Routing the Design”) of “PCB Artist Tutorial INTRODUCTION and TUTORIAL” that is available
in the Appendix of this manual, or at the online www.4pcb.com site.
The purpose of this portion of the lab is to help you to understand the complete design process,
while working with a simple circuit.
As PCB Artist translates your schematic to a basic PCB layout, it may stop and ask you which
component/footprint to use. If this happens, see your instructor.
The Artist PCB layout tool creates patterns on the PCB based on the “footprint” that each
package requires. E.g., the “footprint” for an 8-pin DIP package would include two rows of 4
holes with the holes 0.1” center-to-center. This dimension is the “pitch” of the terminations.
Each lead of the DIP will be inserted a round hole that is surrounded by a solderable pad:
8 pads,
1 footprint:
Pitch
SMT example:
(note that SMT parts generally don’t have 0.1” pitch)
Libraries: within the PCB design function of Artist are a number of libraries. They are in
a hierarchy, similar to the design hierarchy. Three libraries are necessary to define each
component, the Schematic, the Package, and the Component:
Schematic library .shl
Package (footprint) library .psl
Component library .cml
When you select a component in a .cml library, it may have both a schematic portion and a
package portion, or it may have only one or the other, depending on whether it is defined as a
 A complete component
 A schematic-only component, with no footprint – which cannot exist on a board
 A package-only component, with no schematic representation – which cannot exist in a
schematic
As you are continue your introduction to Artist, you will want to use the Help function. Learn the
terminology that’s used with the Help files, since it will help you perform many tasks.
Remember, you can toggle back and forth between the schematic and the PCB layout using the
“Windows” menu pull-down.
When you have completed the op-amp layout with the rats nest, print it out to a Word document,
using the “Print Screen” command.
3.
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XR2206 Schematic Capture
There is not an Exar library in the resident PCB Artist. You will need to locate the
XR2206 in PCB Artist’s on-line “Components Parts Library”. Download it.
Capture the schematic circuit for the XR2206 circuit that you worked with in Lab
Exercise 26 in ECET157, using the schematic capture function of PCB artist. The circuit
from that lab is on the last page of this handout. See the note on libraries on that page.
As you did with the op-amp circuit last week, include all necessary off-board connectors.
BE SURE to include your name in the title block at the bottom of all PCB Artist drawings.
Save your work in your personal drive space with the name 297Lab2 XR2206.
In the following weeks you will convert this schematic to a circuit board file, so the addition of
connectors is important, since we will be doing actual tests on the PCB.
Writeup
The writeup for this lab consists of:
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The Lab 2 cover sheet
The pre-lab sheet, with sketch of the anticipated board mounting and power supply hookup
The op-amp basic PCB printout, showing the rats nest
the XR2206 schematic printout, with the library for each component noted on the printout
ECET297 Lab 2: Reference information from ECET157 Exercise 26
15V
+5V
1k
+
1
10F
7
1k
10k
Frequency Adjust
8
12
4
-
+
AM V
V square
Rt1
sine/triangle
2
V2
XR2206
Rt2
sw1 1k 9
1k
1k
11
Cby
FSK
10
+
Cby
10µF
3
100k
Amplitude Adj.
MULT
CT CT WF
5
1F
6
13
sw2
WF
14
220
Figure 26-1 Function Generator XR 2206 Test Circuit
© T. Fahlsing, 2008
FOR THE ABOVE SCHEMATIC:
Use the appropriate components from the Resistor or Capacitor library, not the generic R and C
from the “Discrete” library:
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Use the SMT components, since that is what you will be using on the PCB
SMT components are designated in the Resistor and Capacitor libraries:
Rs will need to be “0.125W” components, with the lower pulldown selected to “R1206”
A resistor designation will look something like R 0.125W SMTF 1.8K, which means:
An R with a 0.125W rating, an SMT package, and a vlaue of 1.8K ohms
Cs will need to start with “1206” in their number, designating SMT 1206 size, which is
what we have available in MGL1222.
The value for the capacitors is coded in the 3-digit code in the center of the component
i.d. in the Capacitor library. E.g., a capacitor listed as “1206CTR224YHU” means:
o It has a 1206 size and corresponding footprint in the PCB Layout
o It has a value of 22 x 4 zeros= 220000 picofarads, or a 0.22uf value.
Prelab – Check off items as you have them completed – hand in this page by 5PM
in the ECET office, the day before you have lab – 20 pts
Name: _________________________
Lab Instructor:__________________
Lab Date (day/mon/yr): ___/___/____
Lab Day:______ Time: _____-______
___
Explain and sketch how you will mount/package your function generator:
___
Briefly describe your expected use(s) of the function generator, that would define
whether you would use a single supply or a dual supply:
___
Define the power supply for your function generator:
__ single supply, voltage = ___VDC
__ dual supply, voltages = ±___VDC
Supply source(s), e.g. 196 supply, batteries, solar cell, thermoelectric module, ???:
___
Maximum allowable size of a PCB for the $33 “Specials” from Advanced Circuits
is _____ in/cm X _____ in/cm
___
Define your preliminary project board size: ____ x ___
___
Read in the Appendix or on-line: PCB Artist “User Tips Guide” through “PCB Layout”.
Initial here to indicate you have read the User Guide: _______ Date __-__-____