Yes, you can do it with a 555 but the frequency will vary as you change the voltage on the "control pin" or you could use a "PWM" IC. A PIC will work as well.
any ideas on which PWM ICs? or which PIC to use, and where to get any ideas for the code? also I would prefer to go down the PIC route as I need a PIC for other parts of the circuit so should I use assembler code or high level language?
At that frequency, a 555 is ok to create the pulse train, but not to drive the gate of a large MOSFET directly without an intervening gate driver... You will need a high-current gate driver if the pulse train comes out of a PIC, too...
This is a very poor excuse for a high-frequency PWM MOSFET controller. The gate drive is much too whimpy to minimize dissipation in the FET (gate current sourced by 2.2K resistor, sunk by a very slow opamp) . Witness the large heat sink that the FET is mounted on. Very naive design.
This is a very poor excuse for a high-frequency PWM MOSFET controller. The gate drive is much too whimpy to minimize dissipation in the FET (gate current sourced by 2.2K resistor, sunk by a very slow opamp) . Witness the large heat sink that the FET is mounted on. Very naive design.
Yeah definitely. You can get good low-side MOSFET drivers at $0.60 from digikey, look in the appropriate category. No excuse !
You can generate the PWM with the PWM peripheral in your microcontroller, and feed that to a proper driver.
UC1706 looks fine.
This is a very poor excuse for a high-frequency PWM MOSFET controller. The gate drive is much too whimpy to minimize dissipation in the FET (gate current sourced by 2.2K resistor, sunk by a very slow opamp) . Witness the large heat sink that the FET is mounted on. Very naive design.