I am relatively new about semiconductors and I recently realized that driving MOSFETs requires a middle circuit for most microcontrollers. I followed schematics shared in this tutorial, except I couldn't find IRS2001, instead I bought IR2103. I carefully compared datasheets of both and they seem mostly identical or close enough for me. After trying to set a test circuit though, it didn't worked and I have noticed that IRS2001's LIN pin is labeled in phase, whereas my IR2103's is out of phase. ( I connected MOSFET's gate to LO, and triggered from LIN, while supplying 9V to VCC to driver.) I don't know what that means and couldn't find any helpful sources. I noticed that when I connect LIN to 3.3V or 5V nothing happens, but when I connect it to the ground MOSFET starts to conduct, maybe that's related.
If anyone can lead me to something I'd appreciate that. All the other Half Bridge Gate Driver example circuits consisted of two MOSFETs, why is that? Are those two MOSFETs work dependently to each other or independently? What is the actual use of HB Gate drivers? Can I use my IR2103 to drive as shown in the Instuctables link? Also, is it healthy to use common small BJTs as gate trigger circuit instead of a gate driver?
( I'm using IRFZ44N N-Channel MOSFET, which's load will pull around 10-20 Amps. It needs to respond relatively quickly, my guess is around 100 milliseconds at worst. )