I'm trying to build an open source board for PWM-Vaping.
The power is supplied by a 2S battery configuration (5.0-8.4V). I'm using a linear voltage regulator to get 3.3V for the attiny and an oled.
The Output pin of the Attiny drives an MCP1407 as gate driver for an IRLB3813PBF. It works pretty well to up to 5khz. When I raise the frequency further, the fet produces a lot of heat.
Due to my lack of electronic education, I suspect that I'm missing something obvious. Can you give me a hint? Am I using the wrong fet?
No, something is likely wrong about your circuit, you'll have to post it, those devices should be pefectly able to handle even 100kHz switching at high power.
One thing that's essential with this kind of circuit is really tight layout for the high speed high current loop, and decent ceramic decoupling for the main rail and for the mosfet driver.
That driver chip deserves at least 1µF ceramic decoupling no more than a few mm away, due to the massive current slew-rates.
The wiring between it and the MOSFET must be as short as you can make it, a few cm at most, with minimal loop area. Adding a protection 13V zener between gate and source is a useful precaution to prevent voltage ringing from endangering the gate oxide layer.
