Difference between revisions of "An Overview of System-Level Macromodeling Using Virtual Blocks"
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It is important to note that in virtual blocks we only care about the functional behavior, completely ignoring the practical realization of a particular circuit. In the above equations, if we set C = 1F or L = 1H (regardless of the actual physical devices), we will get a derivative relationship between the voltage and current. | It is important to note that in virtual blocks we only care about the functional behavior, completely ignoring the practical realization of a particular circuit. In the above equations, if we set C = 1F or L = 1H (regardless of the actual physical devices), we will get a derivative relationship between the voltage and current. | ||
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| + | <td> [[Image:Diff1.png|thumb|350px|An ideal differentiator using a capacitor.]] </d> | ||
| + | <td> [[Image:Diff2.png|thumb|350px|An ideal differentiator using an inductor.]] </d> | ||
| + | </tr> | ||
| + | </table> | ||
<p> </p> | <p> </p> | ||
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Revision as of 14:54, 18 August 2015
An Introduction to Macromodeling
RF.Spice A/D provides an extensive library of black-box virtual blocks that allow you to quickly test and verify new system concepts without getting into the details of particular circuit realizations. A virtual block typically has one or more input pins and one or more output pins. A system-level function or behavior is modeled by the relationship between the input and output voltages. For example, a multiplier block takes two input voltages and outputs their product. An analog frequency doubler takes a single sinusoidal input voltage and produces a sinusoidal output voltage, whose frequency is twice as large as the input frequency.
Example 1: Analog Signal Differentiation
The simplest voltage differentiator can be made based on the basic properties of a capacitor:
[math] i(t) = C \frac{dv}{dt} [/math]
where v(t) and i(t) are the voltage and current of the capacitor and C is it capacitance. Similarly for an inductor, one can write:
[math] v(t) = L \frac{di}{dt} [/math]
where L is the inductance.
It is important to note that in virtual blocks we only care about the functional behavior, completely ignoring the practical realization of a particular circuit. In the above equations, if we set C = 1F or L = 1H (regardless of the actual physical devices), we will get a derivative relationship between the voltage and current.
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