I am looking at using an IGBT transistor for a project I am working on. The datasheet states that the Gate Voltage is +/- 20volts.

I am trying to use this to amplify the 40kHz, +6/-6volt signal from a 555 timer.

The question is, can I use a voltage amplifier to get the signal up to 20 volts to provide the positive and negative bias for the IGBT or do I need to use an IGBT driver chip?

I have built a couple audio style amplifiers but this is the first time I have used an IGBT.

 

What is the part number of your IGBT?

It's starting to sound like you want to build a Class D amplifier. Is that correct?

IGBT's are a cross between a transistor and an enhanced MOSFET. They have a collector, an emitter, and a gate.

With an N-channel IGBT, generally the collector is in cutoff (not sinking current) when Vge = 0v, and the collector is sinking maximum current when Vge is 10v to 15v.

The +20v/-20v you're seeing is likely the absolute maximum Vge. You really don't want to get too close to the maximums, unless you like replacing your IGBT's frequently.

 

I will have to look for the part number when I get back home from work.

I am pretty much building a class D amp. I am wanting to use it to power a ultrasonic transducer that has a frequency of 40kHz. The transducer has a harmonic resistance of 50Ω.

I was told to try to use a IGBT transducer because it handles the impedience of the load better. Is this correct?

 

Well, IGBTs are easier to drive than transistors, because transistors require a good bit of base current, whereas IGBTs are a hybrid of a MOSFET and standard bipolar junction transistors - you charge and discharge the gate instead of supplying current to a base.

I don't know that you'd get any benefit in using a IGBT over a power MOSFET at low voltages. Usually, you'd want to use a MOSFET for switching DC at low to moderate voltages (say up to 200v or so), and then IGBT's over that. For switching low frequency AC, you'd want to use a thyristor; an SCR or TRIAC. Thyristors, once switched on, stay on until the current through them falls to near-zero.