Siemens.olb Pspice
ECEN 2250, Circuits/Electronics 1 - PSpice Guide PSpiceGuideQuick Links.1. Create A ProjectUnder 'Orcad Family Release 9.2 Lite Edition' select 'Capture CIS LiteEdition'. In Orcad Capture click on 'File', then 'New', and 'Project.' Youshould see a screen similar to the following.If you want to run PSpice later, make sure the 'Analog or Mixed A/D' radiobutton is selected. Choose a directory and a filename and click 'OK'. Select'Create a blank project' in the following window.Now you should be ready to enter the schematic of a circuit.2. Schematic CaptureThe figure below shows the blank schematic page after creating a new projectin Orcad Capture.To draw a circuit, parts are placed on the schematic and then connected bywires.
Ldr In Pspice
Parts are organized in libraries which are added to your project as yougo along. Click on 'Place' and select 'Part.' To obtain a window similar tothe following.Before a part can be selected, its library (located atOrcad92Lite/Capture/Library/PSpice) must be added to the project. For thecircuits 1 and 2 classes the most important libraries are 'analog.olb','eval.olb', and 'source.olb'. The following figure shows the libraries to selectfrom.After adding the ANALOG and SOURCE libraries, resistors, capacitors,inductors and voltage and current sources become available.To place a resistor on the schematic, first select it from the ANALOG libraryas shown next.Then click on 'OK'.
Now move the resistor to the desired location on theschematic and click to drop it.To place more parts of the same type, move to the next location and clickagain at the location where you want the part to go. To rotate, mirror, or flipa part, or to end placing parts of this type right-click on the schematic andselect the appropriate option.Voltage and current sources are in the SOURCES library. The following figureshows the selection of a dc voltage source (or battery).IMPORTANT. Every PSpice project needs a PSpice Ground toestablish a reference potential. The PSpice Ground has symbol, which is differentfrom ordinary ground with symbol. To get the PSpice Ground part, first click on 'Place'and then select 'Ground.' You may have to add the PSpice SOURCE library(PSpice/source.olb).
Then select part '0' as shown below.Place as many PSpice Grounds as needed. Now your schematic is ready forwiring.To enable wiring mode, click on 'Place' and then select 'Wire', or click onthe third vertical toolbar button. Wires ar placed by clicking at the startingnode, if necessary at corners along the way, and then again at the end node.To remove a wire or a part, select it and press the delete (Del) key. Thenext figure shows the circuit diagram, wired as a voltage divider. Note theOff-Page Connector (selected under 'Part' and 'Off-Page Connector.' ) which hasbeen added to show the output of the circuit explicitly.Finally, a title is added to the circuit (click on 'Place' and select'Text.'
), the output connector is relabeled, and the desired element valuesare entered. To change the value of an element, double-click on the currentvalue and enter the new value. The completed circuit, which is ready foranalysis in PSpice, is shown in the following figure.3. Part LibrariesThe following figure shows the PSpice libraries that are available on Orcad9.2 Lite Edition.The most important libraries for Cicuits 1 and 2 are analog.olb,breakout.olb, eval.olb, source.olb, and special.olb. The next figure shows themost commonly used parts and the libraries from which they are available.4. Numbers and UnitsNumerical values for parts can be integers (5, -12, 15) or real numbers(-1.75, 3.1415, 0.7071).
In either case the numbers can be followed by aninteger exponent (1E6, 2.2e-9) or by a symbolic scale factor (530u, 1.2meg).These scale dactors are summarized in the following table. Letter SuffixMultiplying FactorName of SuffixT or t1e12teraG or g1e9gigaMEG or meg1e6megaK or k1e3kiloM or m1e-3milliU or u1e-6microN or n1e-9nanoP or p1e-12picoF or f1e-15femtoLetters which are not sclae factors and which immediately follow either anumber or a scale factor are ignored. Thus, 12, 12V, 12A, 12Hz, 12H allrepresent the same number. Similarly 3.3m, 3.3mOhm, 3.3mV, 3.3MOhm all representthe number 3.3e-3 or 0.0033. Note: A resistor value of 3.3 megaohm isentered in PSpice as 3.3meg or 3.3megohm or 3.3MEGohm, but not as3.3MOhm.5. Element PropertiesSelect any element and right-click on it. In the window that pops up choose'Edit Properties.'
To launch the property editor. This is shown for a resistorin the following figure.Resistors are usually assumed to be perfect in PSpice.
But the resistor modelcan be altered to specify a resistor tolerance, e.g., 10% as shown below.To show the tolerance explicitly in the schematic, select the 'Tolerance'field in the Property Editor and then click on 'Display.' To bring up aDisplay Properties window as shown below.Select the desired Display Format and then click 'OK'6.
DC Bias Point AnalysisThe simplest type of circuit analysis with PSpice is a dc bias pointanalysis. For this analysis only the parts of the circuit that are affected bydc voltages and currents are simulated in PSpice. The results that are obtainedfrom a dc bias point analysis are the dc voltages across all elements, the dccurrents through all elements, and the power absored or delivered by eachelement. As an example, start from the voltage divider circuit shown below.To set up a PSpice simulation, click on 'PSpice' and then select 'NewSimulation Profile'. Enter a filename for the simulation, e.g., dcbias as shownbelow.Click on 'Create' and then choose the 'Bias Point' option in the window thatpops up.
Leave the checkmark options blank as shown in the next figure and thenclick 'OK'.Now you're ready to run PSpice by selecting the menu option 'PSpice' and then'Run'. The output from the simulation can be a text file, a plot, or both. Forthe simple example used here no parameters vary and thus no plot is generated.To see the text file, select 'View' and then 'Output File'. A portion of this isshown in the next figure.As expected, the voltage at the output connector (OUT) is 5V. A handy featureof the Orcad Capture application is that the voltages, currents, and powerscomputed during the Bias Point simulation can be viewed directly in theschematic as shown below.Use the 'V', 'I' and 'W' buttons on the horizontal menu bar to turn thevoltage, current, and power results on or off.7. DC Sweep AnalysisHere is the schematic of a voltage divider with IPFRINT and VPRINT1 devicesto record the current into the voltage divider and the voltage at the output ofthe voltage divider. IPRINT and VPRINT1 are both from the SPECIAL PSpicelibrary.
Note: VPRINT1 always measures voltage with respect to (PSpice) ground.Use VPRINT2 to measure voltage between two arbitrary nodes in the circuit.To obtain an output from IPRINT and VPRINT you need to specify what theyshould record. Click on the print device to select it and then right-click andselect 'Edit Properties.' In the Property Editor enter 'Y' in the 'DC' columnas shown below for the VPRINT device. This tells the VPRINT device to print dcvoltages. Repeat for IPRINT to print dc current.Next, click on 'PSpice' and select 'New Simulation Profile'. Enter a name forthe simulation profile in the window that pops up.The sweep variable in this example the voltage source V1.
For this example V1is swept linearly from 0V to 20V in 1V increments.Click on 'PSpice' and select 'Run' to run the DC Sweep analysis. To see theresults from the PRINT devices click on 'View' and then select 'Output File' inthe PSpice result window. Scroll down to the columns headed VV1 (the voltage ofthe source V1) and I(VPRINT) (the current recorded by IPRINT).Similarly, scroll down to the columns headed VV1 (the voltage of the sourceV1) and V(OUT) (the voltage recorded by VPRINT1 at the off-page connectorlabeled Out).8.
Breakout Diode (LED)9. Nonlinear Resistor (Lamp)10. Element Parameter Sweep Analysis11. Worst Case AnalysisReal resistors have tolerances, e.g. Plus/minus 5% and this affects thebehavior of circuits.
Siemens.olb Pspice 17
By default the PSpice model assumes perfect resistors withresistance values exactly as specified. The voltage divider circuit below isused to show how resistor tolerances can be simulated and how a worst caseanalysis can be used to see to which extent these tolerances can affect theoutput from the circuit.To specifiy a tolerance for a resistor, first select the resistor, thenright-click on it and select 'Edit Properties.'
Scroll to the column labeledTolerance and enter 10% as shown below.To make the tolerance setting visible in the schematic, select the Tolerancefield and then click on 'Display.' Check the 'Value Only' button as shownnext.Repeat this for all resistors whose tolerances you want to take into account.Then generate a new PSpice simulation profile.Select 'DC Sweep' for the Analysis type and fill in values for the desiredrange of input voltages (or currents).Next choose the Monte Carlo/Worst Case Option and select the'Worst-case/Sensitivity' button. Specify the output variable and choose to varydevices that have device tolerances only (no LOT tolerances).Click on the 'More Settings.' Button and specify the function to beperformed (YMAX, MAX, MIN) by the simulation and the Worst-Case direction (Hi orLow).Here is the schematic of the voltage divider, ready for worst-casesimulation. The goal is to find out what the output voltage will be for theworst combination of resistance values for R1 and R2 within the specified 10%tolerance.After the simulation you have to choose which results should be displayed inthe plot window.
The Available Sections shown below are NOMINAL and WORST CASEALL DEVICES. Select both so that you can see the difference between the outputof the ideal and the real (with tolerances) circuit.To see where a particular trace came from, right-click on it and select'Information'.Now suppose that rather than displaying V(OUT) versus VV1, you'd beinterested in plotting the ratio V(OUT)/V(IN). To do this, first select 'Trace'and then 'Delete All Traces' as shown below.Then, again under 'Trace', select 'Add Trace.' Select the V(OUT)Simulation Output Variable first, then type a '/' in the Trace Expression box,followed by selecting the V(IN) Simulation Output Variable.Click 'OK' to obtain the following graph that shows the nominal V(OUT)/V(IN)ratio at 0.333 and the worst-case (in Hi direction) V(OUT)/V(IN) ratio at0.364.Next click on 'View' and select 'Output File' in the PSpice probe window tosee the parameters of the worst-case analysis. The screen snapshot below showsthe worst-case device values (in Hi direction).
Diode In Pspice
Not too surprisingly, the valueof resistor R1 is reduced by 10% whereas the value of resistor R2 is increasedby 10%.Finally, the next figure shows the summary of the worst-case analysis. Itshows that the output voltage is 0.4636 V higher (than the nominal value of 5 V)for the worst combination of resistance deviations due to resistor tolerances.12. Monte Carlo Simulation13. Transient Analysis- To be completed -14. AC Sweep Analysis- To be completed.