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Mixed Signal ASIC Design using ViaDesigner - Video Tutorials

ViaDesigner by Triad Semiconductor is an easy to use mixed signal design environment for developing analogue and mixed signal circuits using Via ConīŦgurable ASICs.

Praxis Dynamics develops video tutorials showcasing a broad range of design, simulation and analysis abilities of ViaDesigner, using real life design examples.
8 Aug, 2014
Key words: ASIC, Via Configurable Array (VCA), ViaDesigner, VHDL-AMS, Video Tutorial

Solution of Implicit Equations in SPICE

Using a simple feedback topology, it is possible to solve implicit equations directly in SPICE simulators during time domain simulations. This approach allows the engineer to simulate a variety of complex multiphysics models directly in SPICE, models that may otherwise require specialized numerical software and laborious post-simulation integration of the results.
In the example discussed in this paper, the micromechanical pull-in effect is simulated with very high accuracy. It is shown, however, that a good understanding of the underlying model is needed, and careful choice of simulation parameters based on preliminary analytical analysis is required to ensure that the simulated system converges to a physical and stable solution if one exists, and deals correctly with cases in which such solution is not present.

4 July, 2012
Key words: Implicit equation, SPICE, feedback, MEMS, pull-in

Modelling of a Linear Second Order System in SPICE

A cross-domain simulation in SPICE requires creation of models that correctly describe the behaviour of mechanical, optical, and other subsystems included in the simulation. One of the most popular models, the linear second order system, which represents an archetypal resonator, can be implemented using a simple RLC circuit. The possible configurations (series, parallel, Pi) are described in this paper, including the governing equations, all relevant parameters, and initial conditions. In addition, a general behavioural model is described. This model should be preferred if the resonator that is being modelled has some non standard features, such as negative damping, or possible addition of nonlinear terms.

26 May, 2012
Key words: Second order system, resonator, SPICE, behavioural modelling