|
|
|
|
ICAP/4 is Intusoft's fourth generation analog and mixed signal circuit simulation package (ICAP/4 brochure in pdf format, 293k). The basic package consists of:
- IsSpice4, a Berkeley SPICE 3F.5 compatible simulation engine combined with the Georgia Tech XSPICE event driven simulator. (Feature set, Details)
- SpiceNet, a revolutionary new schematic entry program that manages multiple circuit configurations and controls the simulator.
- IntuScope, a heavy duty programmable waveform viewer.
- Model Libraries. The EDA industry's largest and most extensive library. Over 18,600 models are available in a series of libraries that varies by product.
These core programs and more are integrated into a seamless package using Microsoft's ActiveX (formerly OLE) technology. Learn What's Makes Intusoft Different?
ICAP/4 is sold in a family of software packages with varying capabilities that were built to provide features you need at the right price. Here is the current product line up:
- ICAP/4Students, a limited circuit sized educational version
- ICAP/4Rx, Full IsSpice4 kernel simulation and analysis, less advanced modeling and post-simulation features
- ICAP/4Windows, the ultimate in Power, Price and Performance, now with automated design analysis and verification
- ICAP/4Windows Power Deluxe, for power specialists
- ICAP/4Windows RF Deluxe, for RF specialists
- Power Supply Designer - Includes ICAP/4Windows Power Deluxe and Magnetics Designer
- ICAP/4 Professional The premiere System, IC, and Board-level simulation and analysis toolset. Now with automatic failure analysis.
- Test Designer, a high end product for failure analysis, product acceptance test program development (TPS) and fault isolation test design
Add on products include:
- CMSDK: The Code Model Software Development Kit, makes the ICAP/4 package extensible. SPICE models are added using a C/C++ language interface with AHDL procedures. Models are dropped in as DLL's in order to extend the primitive SPICE model types without limit.
- SpiceMod: An easy to use program that produces models for discrete semiconductors (diodes, IGBTs, etc.) based on data sheet information.
- Vendor IC models: A compilation of SPICE models available from various semiconductor vendors that are guaranteed compatible with the IsSpice4 simulator.
- Reference Books: Design and modeling examples from the Intusoft Newsletter and independent authors.
- Deluxe Option: Combines the Vendor supplied IC libraries, Reference Books (A SPICE Cookbook & SPICE Applications Handbook), the SpiceMod modeling tool and either the RF or Power libraries in a lower cost bundle.
- RF Device Library: RF device models (BJTs, MMICs, Beads, GaAs Mesfets, etc.) that are accurate for RF design.
- Power Library: Power IC (PWM ICs, etc.) and nonlinear magnetic models
- Mechatronic Library: (Beta version only at this time). Models for mechanical systems including motors, gears, hydraulics, mechanical translation and rotation.
- FilterMaster: Active and Passive filter synthesis tools.
- SALT: Spice Array Linking Technology provides a set of models and a C programming interface to a user defined "node" that can be an N dimensional array. Used for processing data that can be acquired in real time and linked to the core analog and digital simulator.
- Magnetics Designer: A standalone tool for designing and analyzing transformers and inductors. The tool will actually synthesize and design the nonlinear magnetics for you. A SPICE model is also produced so you can simulate your magnetics along with the rest of your circuitry.
IsSpice4
Pioneering PC based workstation simulation, Intusoft introduced its original IsSpice simulator in 1985. Now, several generations of simulation technology later, the 4th generation IsSpice4 simulator combines Berkeley SPICE 3 (Simulation Program with Integrated Circuit Emphasis) analog simulation with the Georgia Tech XSPICE event simulator for a native mixed-signal simulation capability. Added to both of these technologies is an interactive capability that lets you make parameter modifications and watch the simulation results instantly. (Detailed IsSpice4-Berkeley SPICE Differences)
The IsSpice4 simulator uses the Microsoft ActiveX technology to provide an automation interface so that the simulator can be controlled using external scripts as well as the internal scripts implemented in Berkeley SPICE3. Intusoft is the only commercial SPICE vendor that implements and extends the Berkeley script language introduced with SPICE3. This important feature allows IsSpice4 to make and record sophisticated measurements of circuit performance; for example, rise time, gain margin or propagation delay. These automatic measurements are set up and made available to the user through the SpiceNet schematic package.
The IsSpice4 specification describes the analysis types and built in models that IsSpice uses. A feature summary is also available.
How it works:
The simulator itself works by formulating the KCL, Kirchoff current law equations, summing the currents at each node and setting the result equal to a constant. This admittance matrix is modified in SPICE3 to hold the Independent voltage sources and in XSPICE to contain state variables. The matrix itself is referred to as a Modified Nodal Admittance, MNA, matrix.
For DC and operating point analysis, the MNA matrix solution is iterated, and the new MNA values are re-computed at each iteration until a stable result is achieved. Certain circuits like flip-flops can cause the simulator to oscillate between stable solutions. When this happens, the simulator uses certain heuristic tricks to stabilize itself (Gmin stepping, source stepping, …).
An important property of electronic circuits is that connectivity is generally between neighboring parts. If the MNA matrix is ordered along the signal flow, entries tend to fall near the main diagonal with most matrix entries being zero. This is called a sparse matrix and its solution, performed using L-U factoring, is done using an efficient set of procedures that maximizes the sparseness of the matrix by reordering and then using a system of pointers to minimize memory utilization. This makes it possible to solve large systems of equations, i.e. 50000 x 50000, within the RAM limitations of modern workstations.
For transient solutions, it is necessary to linearize the circuit about its non-linear operating point at each time point. Then the dynamic circuit change with time is accounted for by iterating the solution until the error estimate at the next time is less than a pre-established amount. IsSpice4 uses several tricks to reduce the computational load including forward predicting the states and node voltages for the next time step and by bypassing the matrix load operation for parts that have little or no change in their inputs. Many other simulators do not have this feature.
For AC analysis, the problem is considerably simpler. Once the operating point is established, a small signal equivalent circuit is made and a single matrix solution is performed for each frequency. Since no iterations are required, the solution is exact, other than for errors created by the finite computer word length. AC analysis is therefore more precise and faster than transient analysis.
The XSPICE event simulator actually has 2 benefits. The first is to extend the number of primitive models that SPICE can have beyond it original 26 model limit. In accomplishing that, much of the bookkeeping needed to add a SPICE model was swept away, to become the responsibility of procedures added by the Georgia Institute of Technology. Then Georgia Tech added a method of abstracting model properties into a tabular definition that is compiled into C code using their code model software. For models that required event driven simulation, they added the event scheduling software and the whole thing was hooked into the SPICE3 code, mainly in the DCTRAN procedure. Intusoft added a Dynamic Linked Library, DLL, interface so that it is no longer required to recompile the entire SPICE program when a code model is added. You can just drop the DLL into the IsSpice folder and IsSpice will hook the models to itself. The result makes IsSpice perform digital simulation along with analog and provide a really easy method for users and Intusoft to add and manage new IsSpice4 models. An incredible amount of grunt work was eliminated from making an IsSpice primitive model, allowing the user to concentrate mainly on coding model equations. This capability is sold separately in the CMSDK product. Intusoft was the FIRST vendor to incorporate XSPICE technology into its SPICE tools.
IsSpice4 Specifications
AC Frequency response, Bode Plot, Small Signal Linear analysis DC DC source sweep TRAN Nonlinear Transient analysis OP Operating Point DISTO Small Signal Distortion analysis NOISE Small Signal Noise (shot, flicker, thermal) analysis FOURIER Time to Frequency transformation POLE-ZERO Pole-Zero analysis DC Transfer Function Input-Output Impedance and gain TEMPERATURE Circuit and Part Temperature sweeps SENSITIVITY Works for AC, DC, Transient and OP analyses using Perturbation analysis Design Validation Automatic User-defined Measurements matched against test limits, includes summary report Stress Alarms Automatic user defined Alarms monitor any circuit quantity, includes summary report of failed tests PARAMETRIC Parameter sweeping analysis with the Curve Family wizard (Interactive, batch or script style) MONTE Monte Carlo statistical yield analysis OPTIMIZATION Single parameter, single nonlinear function optimization RSS Root Sum Square EVA Extreme Value Analysis Worst Case Worst Case Analysis with sensitivity sign change warning ICL, Interactive Command Language Combination of any/all of the above using a scripting language, accessible from Visual Basic or ActiveX Built-in Transient Signal Generators (many other generators are available in the ICAP/4 models libraries (NTSC, 3 Phase, Sawtooth, FSK, PSK, Random Noise, Repeating PWL with data from a file, etc.)
- PULSE Pulse
- SIN Sine or damped sine wave
- PWL Piece wise Linear
- SFFM Single Frequency FM
- EXP Exponential pulse
Integration Methods
- Trapezoidal
- Gear
IsSpice Models (Built-in)
Analog Behavioral Modeling
Analog C Code (AHDL) Models
Hybrid C Code (AHDL) Models
- Digital-to-Analog Node Bridge
- Analog-to-Digital Node Bridge
- Digital-to-Real Node Bridge
- Real-to-Analog Node Bridge
- Analog-to-Real Node Bridge
- Voltage Controlled Digital Oscillator
Real (Sample-Data System) C Code (AHDL) Models
- Z-Transform delay
- Gain Block
Digital C Code (AHDL) Models
- Buffer
- Inverter
- And
- Nand
- Or
- Nor
- Xor
- Xnor
- Tristate
- Pullup
- Pulldown
- Open Collector
- Open Emitter
- D Flip Flop
- JK Flip Flop
- Toggle Flip Flop
- Set-Reset Flip Flop
- D Latch
- Set-Reset Latch
- State Machine
- Frequency Divider
- RAM
- Digital Source
- MIDI Digitally Controlled Oscillator
Salt Models (with model source code)
Did You Know Intusoft Was the First?
The following is a list of capabilities that Intusoft introduced to the analog simulation world.
SPICE 2 Models for: IGBTs, fuses, lasers, vacuum tubes, generic template models, dual gate Mosfets, SC filters, neural networks, digital gates, RF beads, IBIS buffers, saturable cores, and PWMs (using the state space approach)
Products/Features: 32-bit version of SPICE for DOS, integrated schematic entry dedicated to SPICE, SPICE 2 compatible model generation software, support for all Macintosh platforms, parameter passing