Where can I get transformer models for Spice simulation?

[maxwellequ]

Transformer model

I need to use a mini transformer to generate the differential input signal to apply to an ADC (the signal generator is single ended) - see, for example

**broken link removed**

I need to apply input signals ranging from 10 MHz to 500 MHz.

I would like to perform some SPICE simulations including the transformer model and the input network of the ADC, but I cannot find any transformer SPICE model in the manufacturers.
Does someone know where I can find such models, or information to make one ?

Thanks.

 

[flatulent]

Re: Transformer model

You can use the built in SPICE modeling method by having two inductors that are equal to the transformer open circuit primary and secondary inductances. Then couple them together with (k=0.99 or so) the mutual inductance command.

Then make a test circuit simulation with the transformer driven by a voltage source and a resistor load on the other side. Check for the frequency response matching the data sheet values. Adjust the k value to match. Larger k makes the bandwidth larger etc.

0<k<1.0000

 

[papyaki]

Re: Transformer model

Hi,

look at these application note from Midcom :

h**p://www.midcom-inc.com/tech/pdf/tn82.pdf
h**p://www.midcom-inc.com/tech/pdf/TN69.pdf

With some of the parameters given in datasheet, maybe the generic model described in tn82.pdf can help you.

Regards

Replace * by t