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Electronics => Beginners => Topic started by: LinuxHata on May 29, 2024, 04:51:34 am

Title: Any switching controller with built-in booster for mosfet gate driving?
Post by: LinuxHata on May 29, 2024, 04:51:34 am

Hello. I'm making a flyback converter, which delivers up to 20W into load at 200-400V voltages. power supply is 3-5 volts.
I have to use high voltage mosfets, like IXTQ82N25P (yes I know this is an overkill, but I have a lot of them in stock), which require strong and high voltage gate driver (no logic level hv mosfets are available for CHEAP).
So far, I'm making them in the following way - SX1308 boosts input voltage to 15V, from which, UC3843 is operating and driving mosfet.

Everything works fine and efficiency is quite good. However, I'm curious, whenever there's an integrated solution (controller+booster), which can internally boost low input voltage to drive high voltage gate mosfets? I was not to able to find any...

Thanks in advance.

Title: Re: Any switching controller with built-in booster for mosfet gate driving?
Post by: Berni on May 29, 2024, 05:17:20 am

That's not all that common functionality for dc/dc controller chips.

But they do often have a pin that supplies power to the internal gate driver. So you can use a small boost dc/dc chip to generate the 15V and feed that to the controller chip to use as gate drive.

But if you have a particularly hard to drive MOSFET with a crap ton of gate capacitance, then you might want to be using a separate gate driver chip anyway to get a >5A gate drive current or something.