Tutorial Spice

Orcad Capture Tutorial
This tutorial will teach you to create and simulate circuit schematics with Orcad Capture CIS, to understand various stimulus types and their corresponding analysis types, and to determine desired results and understand how to achieve correct results.

1. Opening Orcad Capture
a. In one of the CEAT computer labs, go to Start -> Programs -> Cadence PSD 14.2 -> CaptureCIS. b. When prompted with Studio Suite Selection, choose PCB design expert with Capture CIS (see Figure 1) from the drop down menu.

Figure 1 - Studio Suite Selection c. Select File -> Project. From the New Project window, give your project a name, select “Analog or Mixed A/D”, and select its location (see Figure 2). You’re now ready to create your schematic. Note: The directory you place yourproject in must already exist.

Figure 2 - New Project Window

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2. Creating Schematics with Capture CIS
a) Next we must draw the desired schematic. To get parts, go to Place -> Part…(see Figure 3). Shift+P allows us to reach this dialog box quickly. Note: If no parts are visible in the “Place Part” dialog, simply click on the “Add Library…” button. Inside the Browse File dialog, click onany *.olb file the press Ctrl+A to select all the files (or Ctrl+Arrow to select certain library files) and hit the “Open File” button. Note: The library files we will be using should be in the directory C:\Cadence\PSD_14.2\tools\capture\library\pspice

Figure 3 - Place Part Dialog b) Let’s draw a simple RLC circuit. We will find the parts we need by typing the name of the part in the Partsection and clicking “OK.” So, let’s draw the circuit below.
R2 100 V1 = 0 V2 = 10 TD = 1u TR = 1p TF = 1p PW = 1u PER = V1 R1 10k C1 0.01u L1 150mH

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c) Remember we always need a ground in the circuit, this can be found in the Place Ground menu, accessible by clicking the button on the right side of the screen. The ground we will use is the .

0/SOURCE identified by the symbol

d)Moving, rotating, and other part manipulation functions can be accomplished through the Edit menu at the top of the screen or right click with part selected. Warning: When making changes be careful- parts may become disconnected.

3. Circuit Simulation
a) After all desired components are in place, go to PSpice -> New Simulation Profile. (see Figure 4). Name your simulation profile and click onCreate, then the “Simulation Settings” (see Figure 5) dialog will appear.

Figure 4 - Naming Simulation

Figure 5 - Simulation Settings

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b) Select the correct analysis type for desired output. Then further change the options for a more specific analysis. Once desired options are selected, click “OK.” To actually run the simulation, select PSpice -> Run.

4. Types of Stimulus and AnalysisEach type of source is actually paired with a certain type of analysis, and in most cases with only one. The primary sources we will use in this class are VPulse, Vsin, and Vac. These are available in the standard PSpice libraries you added when you created the schematic.

4.1 VPulse
It is used to measure the transient response of a circuit. For Vpulse, we control all aspects of generatedpseudo-square wave. Factors directly affecting produced Vpulse function are visible in Table 1 below. Table 1 Vpulse characteristics [1] Pulse Parameter V1 V2 TD TR TF PW PER Explanation Starting voltage for pulse Second voltage for pulse Time delay. Voltage will remain at V1 until this specified time. Rise time. Time required to reach V2 from V1 (Rise time must not equal zero). Fall time. Timerequired for voltage to change from V2 to V1 (Again, fall time must not be equal to zero). Pulse width. Amount of time pulse remains at V2. Period of pulse. How often pulse actually repeats itself

a) VPulse combined with the Time domain (transient) analysis. Let’s take the following example of an RLC network. First draw the following circuit.
R2 100 V1 = 0 V2 = 10 TD = 1u TR = 1p TF = 1p PW = 1u...