MCP1406/07 MOSFET DRIVER

[TinselKoala]

Well, my Class E sstc is a self-resonator oscillator, so it makes its own gate drive pulses from a DC-biased pickup loop under the primary.

You might like to take a look at the technique Steve Ward uses for his HF SSTC.

Try the LTC1799 oscillator chip instead of a 555.

http://i.ebayimg.com/t/1KHz-to-33MHz-Adjustable-Oscillator-Module-LTC1799-/00/$(KGrHqR,!jIE5eKtBB!9BOewH!3opQ~~_12.JPG

[Jeg]

Interesting ways for mosfet driving! I think LTC is fine for me. I already ordered it! Thanks Tins..
I have worked many times with Irfp460 and i never had problems using 555 + comparator for PWM driving. !2V pulses up to about 400KHz. It is my first attempt to drive it in MHz range. Well, will see!
 

[TinselKoala]

Yes, keep us posted on your progress!

For good operation at HF you will need to use good layout and construction, a printed circuit board if possible but if not, then short, soldered wiring, not too many clipleads!

Also some  20 V "gate protection" zeners, back-to-back (or "front to front", I mean in series and oppositely oriented) and from gate to source, right at the mosfet pins, may help to protect your mosfet when you are hitting the gate with the 18V drive.

[Jeg]

Hey Tinsel thanks for the zeners advice.
I finally found my mistake. Between 555 and MCP driver there was a nand gate in which two legs there was coming the same pulse from 555 with a small artificial phase difference, so to create a pulse as short as it could be. But, this was over-driving the driver up to a fatal level even if the input wasn't more than 4.97V. I still don't know why as nand gate is cmos and cmos is compatible for MCP input. But, after i had taken it out, the driver was working fine.

Thanks
Jeg

[TinselKoala]

Good that you found your mistake.

Not so good that you didn't mention this NAND gate chip before when you were asking for help! 4011? 7400? What you get out from such a chip may not be the same pulse voltage level that you supply it from the 555, but more like your Vcc supply voltage.