</table>
== Example: An Analog Integrator Macromodel ==
[[Image:Integ1.png|thumb|400px|A practical voltage integrator circuit using an Op Amp.]]
Note that XSpice provides a similar virtual block called "s-Domain Transfer Function Block" that also features a "Denormalization Angular Frequency" parameter expressed in rad/s. It also allows you to define gain and input offset [[parameters]] and set the initial condition for the integrators.
== A Digital Integrator Macromodel ==
The counterpart of an analog integrator with the transfer function s<sup>-1</sup> in the digital signal processing world is a digital integrator with a Z-transform transfer function z<sup>-1</sup>. This is indeed a discrete-time delay operator. We can use the standard Spice model of a lossless transmission line (TRA) to introduce an arbitrary delay.
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