A famous textual circuit simulator with a number of graphic front-ends. Please tag with the precise flavor used (e.g. Pspice, LTspice, ngspice, Multisim, Proteus, Qucs) whenever appropriate (e.g. syntax or debugging) because there are substantive differences between implementations.

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1N270 Spice Model

Does anyone have the spice model for the 1N270 Germanium Diode? I have found several online libraries of spice models for diodes, but none of them have the 1N270. A google search didn't find it, ...
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62 views

How to simulate BJT cut-off in SPICE

In BJTs, when applying the parameter of collector and base current cut-offs, everything below a given cut-off current gets floored to 0mA, right? So say if we have a configuration with good voltages (...
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228 views

Simulation model for floating gate

I am designing a non-volatile memory cell and foundry does not have model for floating gate . So I used the Voltage controlled current source to mimic floating gate. For output characteristics, I ...
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25 views

How does Spice parse a netlist?

From this discussion about Spice internals, it looks that Spice builds a matrix for a netlist. I wonder how it does it in detail, e.g. for to write a simple parser. E.g. : ...
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8 views

Extract SPICE model from ADS workspace

I'm trying to simulate a SPICE model of a component (a transistor exactly). The manufacturer only provides an ADS archive (.zap) which I opened in ADS : I'm trying to get a SPICE file from this but ...
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2answers
59 views

How to define the initial charge of a capacitor in SPICE

I would like to simulate a circuit with a capaciot in LTSPICE. In the first hand, I have tried to charge the capacitors in a period of time. However, the charging current is very high and I am not ...
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34 views

Signal Transformer Characterization for SPICE

I would like to capture the dynamics of a signal transformer (make a good model of it for spice) . I can characterize the transformer as a band pass filter with a gain, or use the built in ...
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2answers
47 views

Schmitt Trigger does not go to ground

i would like to create simple circuit to drive an computer fan (12V, 0.5A) is the temperature is above 42 celsius and stop when the temperature decreased below 36 celsius. I am simulating in LTSpice. ...
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2answers
219 views

Using Spice/PSpice (Vishay optocoupler) models in LTSpice

I am trying to use the Vishay-provided spice models of the 6N137 high-speed optocoupler in LTSpice. (Source: http://www.vishay.com/optocouplers/list/product-84732/) Both the "PSpice" model and the "...
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1answer
26 views

convert a .s2p file to spice model

can someone suggest me a way to convert .s2p (touchStone) files to spice models. I have checked with various sites like www.emwonder.com and www.spice-club.com suggested in some Forums but it really ...
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57 views

Why Doesn't SPICE Show the Discharging of a Capacitor after Input Voltage is Removed

I have a very simple circuit that includes a capacitor meant to provide a few seconds of battery-like backup to a few LEDs when power is removed. In real life, it does exactly that. However, when I ...
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39 views

How to use a subcircuit in capture / spice

I am wondering how to add an IGBT .subckt file to a schematic in Orcad Capture. I already found out that if you have an '.NIGBT' model, you can use the Breakout library. But I cannot find out how to ...
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18 views

Relabeling pin names of a model without replacing pin names

After downloading a model with pins only labeled as what seems to be hexadecimal numbers. I want to relabel the pin names. As the pin names contain integers, "find and replace" all pin appearances ...
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55 views

PSpice to HSpice conversion of a Transformer Rectifier Power Supply Circuit?

I was able to simulate the circuit in PSpice Student version, for the attached schematic. I am in the process of modifying the netlist generated in PSpice to HSpice , for which upon execution I get ...
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98 views

How to change the temperature of sub-circuits in LTSPICE

I have subcircuits of a solar cell (resistors and diodes) in LTSPICE. I want to connect the solar cells (sub-circuits) together. However, each solar cell has a different temperature. I can set the ...
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21 views

Are dependent resistor values possible in Xyce?

I need my resistor to be a function of a node voltage in order to simulate a battery. I can do this is ngspice by setting R=2*v(1), for example. Is this possible in Xyce (or is there a workaround)?
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52 views

Spice modeling of a comparator using zero-pole transfer function

I'm designing an open-loop comparator for an analog IC. I've followed the design procedure included in the "CMOS analog circuit design" by Holberg and Allen. I've established the required gain and ...
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40 views

Uniqueness of Transient Node Voltages [closed]

Considering only transient (not DC) simulations for circuits in which every node has a capacitor path to any other node (a stack of capacitors connects any pair of nodes), and in which all initial ...
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2answers
60 views

Demonstrating back EMF on an inductor in LTSpice

I'm trying to demonstrate back EMF on an inductor in LTSPice with this model: https://dl.dropboxusercontent.com/u/16979265/Draft2.asc I'm expecting the voltage on the inductor to have a negative ...
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57 views

simulating a electrical transformer

My goal is to program a FDM simulation of a transformer. So, we have the coupled inductor model to start with ... However, if L1 = 1, L2 = 9, and coupling is perfect then M = sqrt(1*9) = 3 and L1 - ...
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4answers
82 views

High Pass filter gain at higher frequency than cutoff frequency

As i know , it's very common easy to find cutoff frequency and calculate gain at highpass filter. This is my circuit; simulate this circuit – Schematic created using CircuitLab My ...
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47 views

Orcad Capture add component via Breakout library

I want to link an IGBT .mod file to the model provided by the breakout.lib (ZbreakN) of Orcad Capture. I added the component of the breakout library, right-clicked, 'Edit Pspice model' and then pasted ...
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55 views

LTSpice parametric subcircuit instances

I want to compare signals from my fancy subcircuit (very complex) and multiple subcircuits level1 (should be almost equivalent, ...
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111 views

noise calculation for LM741 [closed]

my circuit is very simple, i want to calculation output when i apply 0 amplitude sine-wave to do circuit from datasheet, ...
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1answer
46 views

Open pin in circuit, how do I represent that in a spice model subcircuit?

I have a lm386 circuit that requires pin 8, gain8, to be disconnected in the circuit. So how do I write the spice subcircuit to account for no connection in the 8th pin? Example ...
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51 views

worst case analysis

I am trying to a worst case/monte carlo analysis of the following circuit. How do I proceed with ? I have Altium and PSPICE(the textual one and not schematic capture). The main components I want to ...
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35 views

ngspice - Measure param

I'm trying to post-process a value computed by a measure statement in ngspice (rev 26) as described in the manual: ...
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2answers
70 views

How signficant is leakage inductance in a flyback converter?

In designing some flyback DC-DC converters (to give us isolation), we have been simulating potential designs in LTSpice, which has gone well. (Isn't LT great at documentation? Pretty much perfect ...
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41 views

Convert voltage controlled switch into ngspice

I have a circuit file ADA4691 from Analog Devices and it has a different .model V SWITCH versus SW in ngspice with a VON And VOFF instead of VTH for one switching voltage. How could I approximate the ...
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232 views

Using crystal in LTspice (where to get values for RCL)?

I'd like to simulate a schematic in LTspice driven by a crystal. An capacitor representing the crytal (as a resonant circuit) however it needs some specific values. Is there a table of common values ...
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37 views

Array of parts with gschem and gnetlist

Anyone know how, or if it is even possible to create an array of parts/instances in gschem and netlist it with gnetlist. I'm trying refdes=name<0:n> and ...
3
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1answer
90 views

How to add a multi-emitter BJT to LTSpice?

I want to simulate the standard TTL NAND gate which contains a multi-emitter BJT transistor in LTSpice. I've searched the components available in LTSpice but didn't found this component. How can I add ...
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88 views

Is there an alternative to B2.SPICE A/D for Mac OS X?

I've tried B2.SPICE A/D on Windows and I liked it. Is there an easy-to-use application like B2.SPICE A/D that uses SPICE and allows drawing the schematic of the circuit and simulating it?
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53 views

SPICE Programs worth learning for [closed]

I was wondering what are the professional SPICE programs for simulating analog circuits in the industry now. For example, where the big companies like Atmel simulate their microcontrollers, or a ...
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66 views

NGSPICE - Sweep Subckt Parameter

I am playing around with NGSPICE and am having trouble sweeping parameters. I have a subcircuit that is modeled after an Ideal Op Amp. I want to sweep the open loop gain from 1 to 100 and plot Vout. I ...
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1answer
111 views

MOSFET fast turn-off not enough

I have a PWM bridge driving a higher than 1k load from 200V supply. The simplified, equivalent schematic is this: The drivers I'm using are slow turn-on/fast turn-off and, in the schematic, it's a 50%...
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1answer
42 views

Initial Seed for LFSR in PSpice

I am implementing a Linear Feedback Shift Register (LFSR) in Pspice A/D with a new logic family. Anyways, to initiate the random number generation I am required to feed in some value to the circuit, ...
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104 views

.TF Spice Simulation, output impedance with current as output

So I'm currently reading CMOS by R. Jacober Baker and in the first chapter there is a quick introduction into Spice but I have a hard time understanding one of its examples. So this is the circuit: ...
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1answer
56 views

LTspice `Icrating` of BJTs

I see LTspice has an Icrating parameter for BJTs. As far as I can tell this isn't part of SGP (SPICE Gummel-Poon model) and also not present in other flavors of ...
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1answer
56 views

Trying to simulate the linear region of a MOSFET

I wanted to simulate the linear region, so I tried this: simulate this circuit – Schematic created using CircuitLab I expected the triangle wave to be curved, but it didn't have those ...
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2answers
82 views

Automatic parameter search for a given output in LTSpice

I am simulating a circuit on LTSpice and was wondering if there is a way to set output parameters for LT to aim for by adjusting values of other components. I have used some software in the past that ...
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1answer
36 views

Ideal SPICE Model of Op-Amp with Power

I know that the ideal operation amplifier model is a single voltage controlled voltage source. My question is how to extend this ideal model, in a minimal way, to account for power supply rails (V- ...
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2answers
126 views

Simulation difference between two similar OpAmps

I preface this with saying that at one time, many many years ago, I had taken some EE courses. I remember only a little. I was simulating a simple non-inverting amplifier used in a DC setting as a ...
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2answers
868 views

LTSPICE - How to create PWM with rise time

A simple PWM circuit is simple to create using LTSPICE, such as: ...
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75 views

Using SPICE to model dV/dt filter for inverter motor drives

I am starting to learn LTSPICE to create model where I can test various passive filter topologies for inverter drives where the output PWM has very short rise times and high switching frequency. I ...
3
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1answer
108 views

Setting manual thermal voltage for a diode in LTSPICE

I want to simulate some series and parallel connected solar cells with the same reference temperature but different operation temperature for each cell. To do so, I need to configure the thermal ...
3
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1answer
66 views

Buck converter simulation

I am having some troubles to simulate a Buck converter in LTSpice. I added a picture of my schematic in which a use an IGBT (IRGP20B120U-EP from International Rectifier) and a fast recovery diode ...
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1answer
38 views

Is it possible to model a microwave resonator in SPICE [duplicate]

I just wanted to know if it was possible to model a microwave resonator in spice software or somehow import it from somewhere to spice to carry out analysis. Also if it is not possible to model the ...
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2answers
186 views

SPICE modelling of microwave cavities using a circuit

Hi I am new to SPICE and after doing some research into the spice software, I need some help understanding which type and how to model microwave cavities in SPICE. I want to model a microwave cavity ...