I'm building an H bridge form IRF3205 N MOSFETS to drive a TX coil for Wireless power transfer. I want to make the high side switching without a driver, instead I'm using a somewhat similar bootstrap configuration. For testing I use an active 10R load at 12 Vcc. The switching frequency is 100 KHz.
In the blue is VGate relative to ground and the red is signal from microcontroller. If one decreases R1, the edge rising time greatly improves, but at the expense of a lot of R1 and D1 heating because they conduct when Q5 is 'open'. What would be an efficient schematic to make a 'power efficient' gate driving circuit and since I'm not too experienced ir ringing causes, what could be the reasons for the ringing when the gate discharges?