I have seen many high watt like 1200 or 1500 watt boost converters and not a buck converter with that high wattage or power rating . I'm planning to make one buck converter (input- 35 volts output-3 to 35 volts current -30amp max and adjustable ) but is there any restrictions to the power of a buck converter or are there any certain limitation to the current it can output.(I dont want to buy any discrete buck converter ic. I intend to use typical pwm chips like uc38xx ,tl494 etc or even opamps)???
Any limitations will become apparent when you will decide the exact implementation. Will the converter work in DCM or CCM? what kind of switching device are you going to use? are you considering using a μC (for PWM) and transistor drivers or you want a strictly analog device?
You should first answer those questions and then start worrying about limitations.
Things you should definitely check:
- Inductor can withstand the current - this depends on the conduction mode (CCM, DCM)
- Diode can withstand the voltage and the current
- Output cap can withstand the voltage
- Transistor can manage the energy flow and not get burned. Maybe use a snubber?