Why use Gate Driver ICs???? and some other confusions

[Mohammad Zubair]

I have some confusions regarding Inverter

1) Why use Gate Driver ICs like IR2110/2 for driving IGBTs and MOSFETs???
What is their significance???

2) Can I use optocouplers in place of gate driver ICs???

3) If I use a set of p type IGBT as HI side and n type IGBT at lowside, then why do i not need Gate driver ICs???

4) What is the difference between behaviour of IGBTs and MOSFETs like when they conduct and when they don't and etc???

 

[AAOAA]

Are these homework quetions?

 

[FlapJack]

1) Gate driver IC has high output current for fast switching.
2) Opto's are used for isolation not for driving the gates.
3) It has been a long time since i looked at this issue but there were several reasons at the time. P type mosfets were hard to buy in higher current and voltage, and they were more expensive. Also you can easily turn the P type on but turning it off easily you had to use a pull up resistor and that is slow.
4) mosfet can have very low on resistance, igbt uses a transistor for the output so it always has 1.2 to 2.8 volts or so drop on it. But the igbt can switch high voltage and high current.