Take a look at the IR2110 datasheet once, I think that is similar to 
what you want.  It doesn't require optical isolation, as the driver has 
an internal level shifter.

Yea, you loose a couple of volts with an IGBT, but at least that is a 
constant no matter what the current draw is, where as a mosfet voltage 
drop goes up more and more as you draw more current (an IGBT should be 
linear throughout the PWM range).

Harold Hallikainen wrote:

>Thanks! The high side drivers are used in H bridge or half bridge DC
>switching circuits. In their example circuits, there is a common ground
>between the control input and the HV supply. I'm really looking for
>something like an IGBT AC solid state relay, similar to the SCR solid
>state relays. I apply voltage to an isolated input and the output shorts.
>I remove voltage and the output opens. Getting the opto isolation
>generally requires a floating supply to drive the gate. As another poster
>noted, that supply can possibly be pretty simple (diode, resistor,
>capactior, and zener). There's a nice table at the end of the first apnote
>(
>http://www.powerdesigners.com/InfoWeb/design_center/Appnotes_Archive/an-978.pdf
>) that summarizes driving floating devices. It seems that the pulse
>transformer with a clamp to restore DC on the high voltage side could be
>used. The "carrier drive" method seems like it'd have slow turn off. The
>bootstrap method doesn't seem like it'd work if the duty cycle is 100%.
>
>So... I'm leaning towards a opto isolated FET driver driven powered by a
>simple transformerless power supply on the AC line side. It seems simplest
>to use a diode bridge between the line and load with the FET or IGBT on
>the "DC side" of the bridge. Our voltage drops are starting to accumulate,
>though. We've got at least 1.4V across the bridge, plus what, another volt
>or two across the IGBT?
>
>Harold
>
>
>  
>


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