How to choose the correct mosfet for non-inverting buck-boost converter??

Hi...

I am designing a non-inverting buck boost converter which needs to use two mosfet switches with the varying of duty cycle to produce the output ranging from 1V to 10V with an input voltage of 5V and 500mA.
Should I be choosing N-Mos or P-Mos as my two switches for my design?
What are the parameters I should look into that matter for my design?

Thanks...

I found a paper describing a non-inverting Buck-Boost converter **broken link removed**. It suggest two of each type. Four mosfets total.

I don't know if it's possible to make it any simpler.

Hi...

Thanks for ur reply.
However, I'm designing with only 2 switches n 2 diodes. I really got no knowledge on mosfet switch. For wat I know, n-channel mosfet, a gate driven circuit is needed but p-channel mosfet does not need an external gate driven circuit. I intend to use a p-channel mosfet for my buck switch & n-channel mosfet for my boost switch. Can anyone enlighten me??

The following link can help you how to design SMPS Power Supply.

**broken link removed**

I really need help on how to operate N-channel mosfet.
With a 5V power supply and voltage input of 5V to the mosfet's gate and the mosfet's source pin is not connected to the gnd but connected to an inductor.
Is it that the voltage input to the mosfet's gate must be higher voltage than the voltage supply so that the mosfet can turn on?

Most use the boosted output for driver voltage. If output must be variable or below a level needed to run switch gate then a separate pump circuit is needed.

Feeding an N-ch can be done with a bootstrap capacitor for supply feeding a floating driver circuit. Input to floating driver is driven from differential current sources. See IR2101. You can also use the IR2101 with a separate capacitor voltage pump supply feeding floating driver supply.

Look up SEPIC switchers. You can make one with single N-ch. If you want syncronous rectifier then add P-ch. SEPIC's are complicated to design and doing one with syncronous rectifier is even more so.

Four switch buck-boost is simplest with essentially buck on input and boost on output of coil.