Hello,

I have recently started to use HyperLynx so I apologize in advance if the following questions are basic.

There are 3 types of Models for the capacitors:

1) Simple C-LR

The capacitance value, is it the normal capacitance or should we add the DC-Bias characteristics of the capacitor (MLCC) at the voltage? For instance, a 1uF capacitor may be 600nF at 5V.

The ESR, this value depends on the frequency, so what value to we put on the calculation? Minimum or Maximum?

2) SPICE

The help file (file:///C:/MentorGraphics/9.4.2HL/docs/htmldocs/mgchelp.htm#context=hlsipi_useref&topic=7) does not really explain what you have to do. Is there any other document in which this method is better explained?

3) Touchstone

Same as SPICE, there is no much information about this.

I consider that the model type will influence the simulation a lot so I want to be careful and choose the right thing, hence the need to ask.

I appreciate any feedback you can give me.

The selection of model type depends mostly on what type of model is available. A SPICE or S-parameter model is usually more accurate in including frequency-dependent effects and resonances caused by geometry, but not always. A SPICE model needs to be in the form of a subcircuit with the same number of nodes as the component pins. An S-parameter model might be 1 or 2-ports and could be measured with the capacitor in series between 2 ports, or shunted across the terminals of 1 port. When you assign a Touchstone (S-parameter) model, there will be additional options to clarify the configuration of the measurement. You need to get this information from the data provider. If you can't get a SPICE or Touchstone model of the capacitor, then you can resort to the simple lumped element model defined by values. If you know that the capacitance changes with bias voltage, then I would use the value corresponding to the nominal DC voltage between the nets connected to the capacitor.