mosfet calculation parameter

i want to built a boost converter .
my switcher is a mosfet (http://www.nxp.com/documents/data_sheet/SI2304DS.pdf)
1) Knowing that Id =0.4A (or id=0.2 A) and Vd =12 V how can i choose the Vgs ?
2) it's always necessary to use a mosfet driver ?
if yes how can i select it ?
thks !!!

Hi,

What type of boost converter you want to build: isolating or non-isolating ? There are many configuration for the isolating DC-DC converter. You have to choose the one suitable for your application...

You must first choose the switching frequency, output voltage, what core of ferrite do you use in case of isolated converter...
It's not always necessary to use a mosfet driver, tell more about what you want: input voltage, output voltage, isolated/non-isolated, swhitching frequency, regulated or not ...

vin= 2.75
Vout=12V
Fs=1Mhz
it's a non isolated and non regulated boost

Being a swiching converter, you don't really care about Vgs (you are not using the FET in an active mode) except that the control portion of the regulator has to be able to turn the FET completely on. Being a boost converter, your FET source will be at ground, making the task of driving the FET gate easier.

MOSFET drivers are used for obtaining higher switching performance of FETs. Depending on the source of the control signal driving your FET, and the inefficiency and thermal performance tolerated by your design, you may need a driver at 1MHz and you may not. Higher switching speeds and faster transitions are what dictate the need for drivers.

everything you need to know including some free (trial at least) software is at
www.ridleyengineering.com

the design center is here
http://ridleyengineering.com/index.php/register/registers.html
register and you will have access to everything you need

all the best to you

thank you !!

Hi, this is test circuit I have been working on for a buck converter. It still needs some fine tuning, but it does work for a resistive load and for charging applications. I hope this helps

thank you for the links !!!