System Simulation of Analog Circuitry and Digital Logic in NI Multisim and LabVIEW

Publish Date: Aug 07, 2013 | 1 Ratings | 2.00 out of 5 |  PDF

Overview

On this page, learn how to integrate NI Multisim and NI LabVIEW software to simulate a complete system of analog circuitry and digital logic including power electronics, electromechanical components, field-programmable gate array (FPGA) code, and all of the system dynamics between the analog and digital worlds.

For more information, view the tutorials and reference designs at the end of the document.

Table of Contents

  1. What Is Multisim-LabVIEW Co-Simulation?
  2. Relevant Industries and Applications
  3. Improve Your Design Approach
  4. Save Time and Money
  5. Advantages Over Other Simulation Approaches
  6. Multisim Semiconductor Relationships
  7. Tutorials and Reference Designs

1. What Is Multisim-LabVIEW Co-Simulation?

With the Multisim-LabVIEW Co-Simulation feature in Multisim 12.0, you can implement desktop simulation of your entire analog and digital system before prototyping. Accurate point-by-point closed-loop simulation of SPICE-based electronics components and LabVIEW digital controller logic is now possible between the LabVIEW and Multisim simulation engines. Co-simulation now makes it possible to codesign an entire system to help you ensure that algorithms and code simulated for the LabVIEW hardware target are verified for performance with analog circuits and can be directly ported to a supported LabVIEW hardware target such as LabVIEW FPGA with minimal changes. The result is a better system design methodology that features earlier design performance visualization and analysis as well as fewer prototype iterations (and compiles) to save time and improve design performance.

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2. Relevant Industries and Applications

The Multisim-LabVIEW Co-Simulation feature helps users from different engineering backgrounds solve control design problems with graphical system modeling techniques and accurate SPICE modeling.

Industries

Applications

 

  • Renewable Energy
  • Power Electronics
  • Automotive

 

  • Medium-voltage motor drives and pumps
  • Power supplies/power converters
  • Grid-tied solar inverters
  • Wind turbine power converters 
  • Utility scale energy storage systems 
  • Electric and hybrid electric vehicles

Now, these systems, typically implemented using NI Compact RIO, NI Single-Board RIO, and NI GPIC, could be evaluated on the desktop before prototyping into hardware. For instance, complete system simulation of a three-phase grid-tied power inverter including all the power electronics parameters and the coupled dynamics between the digital controller and the power switches at fast switching transients in the megahertz range could be performed. Also, Multisim and LabVIEW offer a seamless transition of the FPGA compiled code and the analog circuitry to a daughterboard to NI hardware platforms.

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3. Improve Your Design Approach

With this feature, you can implement point-by-point simulation of SPICE analog circuitry and digital logic. This exclusive function in Multisim and LabVIEW facilitates a unique time-step negotiation between two simulation engines that allows for closed-loop simulation of the complete system. The Multisim simulation is optimized for accurate analog and mixed-signal circuitry, and you can use the large set of SPICE models in Multisim 12.0 provided by leading semiconductor manufacturers (see a partial listing below) or use your own. The LabVIEW simulation engine helps you effectively design and implement control logic through a graphical, dataflow representation. This engine provides high-level simulation optimized for mechanical simulation.

With the simulation strengths of both environments (including accurate SPICE-level analog simulation), you can create a more accurate characterization of the system including harmonics, transient behavior of motors, and power circuitry. By analyzing this earlier in the design flow, you can take advantage of simulation as an effective tool to minimize errors before moving your system to hardware.

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4. Save Time and Money

Compiling digital logic for an FPGA can take more than four hours. Every code iteration that does not properly account for analog circuitry can result in multiple iterations of code and time lost in compiling and deploying. Accurate co-simulation with analog circuits, which is possible with Multisim and LabVIEW, can reduce prototype iterations to save you time and money.

More accurate analog circuitry simulation can also improve printed circuit board (PCB) prototypes. On average, improved simulation can save as many as three prototype iterations per PCB design. With Multisim simulation, you can evaluate design decisions and reduce prototype iterations in every design cycle.

This approach shaves days off the prototyping time for analog and digital systems.

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5. Advantages Over Other Simulation Approaches

The closed-loop point-by-point simulation between analog circuits and digital systems replaces the conventional approach of simulating both ends separately and then loading the analog simulation output as a batch file into the digital simulator (even if both simulators share the same graphical interface). Many system simulators offer the possibility of simulating digital system blocks and the script/code files of control algorithms and then importing an analog design into the system. But in this case, the digital and analog simulations remain untied, so a lot of system dynamics may be missing in the simulation results, which leads to significant errors. In contrast, the Multisim-LabVIEW Co-Simulation feature offers complete synchronized system simulation that typically results in improved predicted system behavior and accuracy.

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6. Multisim Semiconductor Relationships

NI works closely with third parties to provide a complete end-to-end board-level circuit design experience. Several leading semiconductor manufacturers produce component models that complement the powerful capture, simulation, layout, and routing of Multisim and NI Ultiboard. For Multisim 12.0, NI added over 2,000 new component models to the database from these leading manufacturers alone.

NI also added a variety of new power electronics components models to the database to implement accurate circuit simulations of power and electromechanical designs:

  • Power switches: Take advantage of new generic models for diodes, gate turnoffs, silicon-controlled rectifiers, TRIACs, and transistors with a body diode. You can change the parameters of these generic models to reproduce the response of the hardware components at an early design stage.
  • Power controllers: With new generic models of phase angle controllers and pulse-width modulation controllers, you can model and simulate these devices, which are heavily used in high-efficiency, high-speed power converter applications.
  • Configurable transformers: Use new generic models of configurable transformers to model the behavior of most transformers on the market.
  • Nonideal RLC models: These models can help you better predict the resistive losses and reactive parasitic effects of circuit components.

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7. Tutorials and Reference Designs

For more information, view the following technical resources on how Multisim and LabVIEW co-simulation can improve your design approach.

Tutorial: Introduction to Multisim and LabVIEW Co-Simulation

Reference Design: Simulation of DC H-Bridge Analog Circuitry and FPGA Control Logic in Multisim and LabVIEW

Reference Design: Simulation of a Three-Phase Inverter Circuit and FPGA Control Logic in Multisim and LabVIEW

 

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