please how can a microcontroller be used to drive smps power mosfets.
i tried to drive the mosfets with the mcu but the out put voltage drops significantly to about
40 from the expected 250volts
To fully turn on a POWER MOSFET you need to drive its gate using at least 8v. The microcontroller can not output 8v from its port pins. So the MOSFET is not fully turned on. The current from the microcontroller is also limited. Using a MOSFET driver allows you to drive the MOSFET driver using 5v and the MOSFET driver drives the MOSFET using a higher voltage (8 volt plus, supplied to it through Vcc) while driving the MOSFETs quickly, keeping pretty low rise/fall times.
The circuit topology would determine if you need high-side or low-side gate drive and which driver would be suitable. If you used half-bridge or full-bridge, you will need a high-side driver. For push-pull, flyback, forward, you need a low side driver. For double transistor forward, I think you need to use a gate drive transformer.