Introduction to Elementary Circuit Simulations with PSpice Circuit Laboratory EE. Dept., National Taiwan University September 2013

Outline Where can you access PSpice? To Get PSpice via Cadence OrCAD Site Introduction to OrCAD Demo Drawing Circuits with Capture CIS Bias Point Analysis with PSpice DC Analysis with PSpice Transient Analysis with PSpice AC Analysis with PSpice FAQ

Where can you access PSpice? Two way to get PSpice http://www.cadence.com/ You can find OrCAD 16.6 Demo here. Your disc in Sedra/Smith You can find OrCAD 9.2 Lite here. Which one to use? They are almost the same. You can choose one of them. The following shows the use of OrCAD 16.6 Demo.

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Introduction to OrCAD Demo (1) Free version? No free meal, of course! Limits exist since it is a lite version or a demo The following limits apply to the Demo/Lite Version of the products: PSpice A/D Circuit simulation is limited to circuits with up to: 64 nodes 10 transistors 65 digital primitive devices 10 transmission lines in total (ideal or non-ideal) 4 pairwise coupled transmission lines.

Introduction to OrCAD Demo (2) Limits [cont'd] PSpice A/D [cont'd] The sample library includes 39 analog and 134 digital parts. Device characterization in the PSpice Model Editor is limited to diodes. Stimulus generation in the PSpice Stimulus Editor is limited to sine waves (analog) and clocks (digital). Circuit optimization with the PSpice Optimizer is limited to one goal, one parameter, and one constraint. You can not create CSDF format data files. You can only display simulation data from simulations performed with the Demo/Lite Version of the simulator.

Introduction to OrCAD Demo (3) Limits [cont'd] Capture CIS The PSpice libraries are the only ones included. The standard Capture libraries are not included. Import facilities, netlisters, and accessories that are not relevant to PSpice are not included. You can not save a design that contains more than 60 parts. (You can view or create larger designs, but you can not save them.) You can not save a library that contains more than 15 parts.

Introduction to OrCAD Demo (4) Minimum hardware requirements Pentium 4 (32-bit) equivalent or faster Windows XP, Windows Vista, or Windows 7 Minimum 512MB RAM (1GB recommended) 300MB swap space (or more) DVD-ROM drive 65,000 color Windows display with minimum 1024x768 (1280x1024 recommanded)

Notes When Set OrCAD Demo Up In the procedure installing… Make sure you are connected to the internet. Run “Product/Demo Installation” only. Don’t set the control file. Choose to install “Capture CIS” and “PSpice” only. Keep “Footprint Viewer Options” to be “None.” Cancel “License Client Configuration.” For the first time execution… Run “PSpice AD” first, close it, and then you can run “Capture CIS” and use the function of PSpice.

Agree, of course!

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Close it

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Drawing Circuits with Capture CIS To simulate a circuit, we need to figure out the structure of the circuit. Capture CIS helps us to do that. Create a new project with Analog or Mixed A/D wizard after selecting a proper folder to save. Place the elements (even if it is the ground) that are in the PSpice libraries. Place the tags (if needed) that are in capsym.olb .

Remember to select a proper folder (no Chinese!!) to save C:\OrCAD_Data is welcome to be used

%OrCAD%\tools\capture\library\pspice\demo Add all of them

Frequently Used Elements R (resistor) / L (inductor) / C (capacitor) D (diode) D1N4002 D1N750 MBreakN / MBreakN4D (NMOS) MBreakP / MBreakP4D (PMOS) QBreakN (NPN BJT) Q2N2222

Frequently Used Elements QBreakP (PNP BJT) Q2N2097A uA741 VDC / VPULSE / VSin / VSRC IDC / IPULSE / ISin / ISRC GND

Bias Point Analysis with PSpice Where to find elements? Place → Part or find the “Place Part” button on the toolbar Pick the element you want Click OK button How to link the elements? Find Place Wire button on the toolbar Link the elements you want NOTE: wire crossing without big dot → open wire crossing with big dot → short

Place Wire

Bias Point Analysis with PSpice How to simulate? PSpice → New Simulation Profile Fill out the profile name Select Bias Point in Analysis Type Click OK PSpice → Run

profile name as your wish

DC Analysis with PSpice Note: VSRC or ISRC used! How to simulate? PSpice → New Simulation Profile Fill out the profile name Select DC Sweep in Analysis Type Fill out Name, Start Value, End Value and Increment Never forget to check the type of the Sweep variable! PSpice → Run A/D window

DC Analysis with PSpice Add Trace? Trace → Add Trace... Special Functions Node Variable

Transient analysis with PSpice NOTE: VSRC and ISRC not used! Usually VSin/ISin/VPULSE/IPULSE used How to simulate? PSpice → New Simulation Profile Fill out the profile name Select Time Domain(Transient) in Analysis Type Set Run to time, Start saving data after, and Maximum Step Size PSpice → Run

TR TF PW V2 V1 TD PER

Transient Analysis with PSpice Trick: Axis Settings example: Lissajous Figures Method Plot → Axis Settings... Data Range Scale Fourier Analysis Axis Variable

AC Analysis with Pspice (1) NOTE: VSRC or ISRC used! How to simulate? PSpice → New Simulation Profile Fill out the profile name Select AC Sweep/Noise in Analysis Type Select the frequency scale (linear or logarithmic Decade/Octave) Fill out Start frequency, End frequency, and the information about sampling rate PSpice → Run

AC Analysis with PSpice (2) Trick: Multiple plots in one window example: Bode plot Plot → Add Plot to Window Trick: Y-Axis scale switch (linear or logarithmic) Log Y Axis button on the toolbar

FAQ I faced the dialogs as follows and cannot create or edit any PSpice simulation profile. If you are a WinXP user, you must forget to run “PSpice AD” first in the first-time execution. Close Capture CIS, run PSpice AD, close it, then try to run Capture CIS again. If you are a WinVista user, there are some OS options you need to modify. See another slides discussing the troubleshooting of installation on Windows Vista.

FAQ How do I represent 10-3, 10-6 ,etc., by letter in PSpice? Scale Symbol Name 10-15 F; f femto- 10-12 P; p pico- 10-9 N; n nano- 10-6 U; u micro- 10-3 M; m milli- 103 K; k kilo- 106 MEG; meg mega- 109 G; g giga- 1012 T; t tera-

FAQ How do I change axis scale quickly? Try these buttons:

FAQ What's the difference between C1:1 and C1:2? They represent the different pins of your element. Distinguish the pins very carefully.

FAQ I tried my PSpice, and saved my circuit file upon the desktop, and when I try to simulate the circuit, I get some simulation error about "file not exist" or so on. What's up? It is a tricky bug of PSpice. A filename or folder / directory name with Chinese is not accepted in PSpice. Try creating a new file, copying the original circuit to the new file, and save it in a folder not containing Chinese or spaces, such as C:\temp . Hope this works. Of course, files saved upon the desktop, which is at C:\Documents and Settings\eeuser\桌面 if you use Windows in Chinese version, are not accepted. In Version 16.6, you are suggested to save your design files in OrCAD_Data folder. This helps.