mosfet as a switch in boost converter

[baltzois]

hi,
i am designing a boost converter in hspice and i want a more realistic model than using generic components. So i currently use a G element but i would like to use a mosfet in order to see the switching losses. Can anyboby help me how to choose the best mosfet and what to be careful of??
Thank you!

 

[Mr.Cool]

you need to know your boost converter's worse case applied voltage & current. then multiply that number by 1.3 and find a mosfet with at least that much rating.

then evaluate your losses of conduction vs. switching frequency. try to find a mosfet that will give you average losses of the same value in each while working at rated conditions.

then calculate your power dissipation and ensure that you can cool the mosfet such that the JUNCTION temperature remains 35degC less than datasheet rated worknig value.

Mr.Cool

 

[baltzois]

ok thank you!!i have chosen one!it is irfz24n...
can you help me how from the datasheet to transform it in a model in hspice???
thank you!

 

[Mr.Cool]

spice is a powerful engine which uses the PHYSICS of the device to determine functional performance. if you rely on datasheet parameters you are wasting your time with PSpice.. you might as well use Simulink or PSim.

so.. if you intend to use spice... then you're only chance is to get a model from the manufacturer. if it does not exist, chose a "similar to" or change the part you are using. that is my advice.

Mr.Cool

 

[abhajn]

I am not sure about HSpice, but if you are using PSpice - you can extract model parameters from datasheet parameters using 'Extract Parameters' option in PSpice Model Editor. It uses curve-fitting techniques to extract optimum model parameter values.

 

[snafflekid]

People, most devices are modeled by the manufacturer.

http://www.irf.com/product-info/models/SPICE/irfz24n.spi