Help me understand some values for IR2112/3

Help with IR2112/3

Hello there.
I am using IR2112 (gate driver) for driving the half bridge of my 3 phase inverter. I have figured out the boot strap component ratings and gate turn on/off resistor ratings as according to my application needs. Following are the things I dont understand.

1) The maximum motor current is around 1.5Amps and it operates on 220Vac (name plate parameter). Does this factor have anything to do with wattage ratings of the bootstrap and other gate driving components?? I mean, are quarter or half watt capacitor and resistors are good enough or I have to properly evaluate their power ratings??

2) The power components are IGBT's. On data sheet it is listed that 'Vge - th' is maximum 7V. Does this mean I can not drive the gate at 15V (or geater than 7V in general)

3) What should be the value of capacitor attached to the supply pins of low side supply?? Is it the same as that of boot strap capacitor or is there any way to evaluate its value?? (Pic is attached)

Re: Help with IR2112/3

1. The driver circuit dimensionioning hasn't to do with output rating rather than gate currents. High power tranistors haver usually larger gate capacitance and possibly use higher gate currents (depends also on the intended switching speed).
2. It's a threshold voltage, the gate driver supply must be considerably higher than it. 15 V is O.K for any standard IGBT or MOSFET.
3. It's O.K. to chosse the same value, but it's less critical than the bootstrap cap.

I have designed the circuit as according to your reply, instructions given in IRF application notes and in data sheets (to some extent). In addition to that, I have also taken help from reference designs available on the internet.

What I am talking about at the moment is the single phase of the three phase inverter (as if single phase is good, then the other two will just be a matter of copy and paste). For the time being I have not connected AC motor to the output and have been performing test on DC motors (as outputs).

The low side is working fine i.e. a high at the input gives a high at the output (as long as the input is high). BUT, I am not sure about high side. A high at the input drives the output high for about, say, 3 seconds and then the output goes low. Does this thing have anything to do with re charging of bootstrap capacitors or there is a error in the circuit?