Last changed 2005-May-1
Design entry for printed circuit implementation is not significantly different than for analog or digital simulation, except that only parts from the Board Process Library may be used in your design. Using any parts from the genlib, Accusim library, or Digital library will cause errors that will prevent you from successfully starting the circuit board layout.
Start Design architect by typing:
hoodoo:/home/stirra/classes/engr357/pcbtut> run_en2k da
Click on the "Open Sheet" icon. Pick a name for your new circuit and enter it in the dialog box. For this tutorial, the circuit name is "osc1". Do NOT change the sheet name, startup file path, or any other options.
Once you have a blank sheet inside DA, select the "Library" icon. This will give you the top level index of Board Process Library categories. Remember to use only parts from this group of libraries in your design (no Accuparts or generic library parts).
Our sample design will be of a simple JFET amplifier. Select the Active Discrete parts, and the WWC NJFET submenu. Normally, if your part type is available in a WWC specific submenu, use that part, rather than the same or similar type in a non-WWC menu. This will help you restrict your choices to parts we are likely to have in stock. Select List Parts, and choose the J310 part. Click on "Refine Component", and select the SOT23 surface mount package type. You can now place your component on your schematic.
Next, place resistors on the schematic. There are many styles of resistors available in the BPL. For surface mount, use 0805 size (DK 5% SMD 0805 style from the BPL resistor library), or for through-hole boards use 1/4W (DK 5% PTH 1/4W style) devices. Ask your instructor before using any others, as we likely don't have other packages and values in stock. For this example we will use the 5% 0805 SMD type. Choose a value for your resistor using the "Choose value" form, so you don't end up with a non-existant value.
Capacitors also come in many styles, and you need to be sure you understand what type is needed for your circuit. The library includes ceramic, film, electrolytic, and tantulum types, many in both surface mount (SMD) and leaded (PTH) styles. Most of your boards will use 0805 size ceramic surface mount caps (DK Pan SMD 0805 style in the BPL capacitor library) or monolythic ceramic leaded type (DK Pan Mono).
For ENGR357, you will be placing your circuit on a standardized board. This board will be either 2in x 2in or 2in x 3in in size. There will be two standard connectors on the board, one on the left and one on the right. Use the 8-pin connectors under the "Other" library, "Connector: ENGR357 Boards" menu. The "Left pins" component is for input signals, and the "Right sockets" is for output signals. You must always "Refine Component" and choose the exact part before placing it on the schematic. The signals on these connectors should use the convention (from top to bottom): V+, GND, V-, SIG0, GND, SIG1, GND, SIG2. You also need to place the RFCAN symbol (from the "Other" menu) on your schematic and connect the four pins to ground.
For convenience, we may wish to indicate power and ground signals on the schematic. These are chosen from the Connectivity Symbols menu. Use the "vcc" symbol for the positive supply and "vss" symbol for the negative supply.
Connect your parts using wires, not busses, by clicking on the "Add Wire" icon. A single left-click fixes a vertex of the wire, and a double-click ends the wire.
It would also be a good idea to get in the habit of putting a title block on each schematic. This is obtained from the "Other" menu. After you have placed the title block, you should draw a little trace between the two dummy pins on the right hand edge (this will eliminate a warning when you check your sheet later). You also need to update the date stamp in the title block with the Edit->Update Title Block menu pick. You also should change the title in the title block to something appropriate (most easily done by positioning the cursor over the title and pressing shift-F7 on the keyboard). The engineer's name or initials can be changed the same way. Finally you will have a title block that looks like this.