I have seen several high-side MOSFET drivers which are internally isolated. As I can understand, isolated gate driving is a fairly new technology, since they encapsulate all the complexity in a single chip.
One such driver is the ADuM3322x (thanks to comment below), which is an isolated 4A Dual-Channel Gate Driver, designed to drive N-channel MOSFETs:
In the datasheet it is stated that,
The ADuM3220/ADuM3221 digital isolators require no exter-nal interface
circuitry for the logic interfaces.
If this driver is indeed intended to drive a high-side MOSFET, there needs to be an added bootstrap circuitry, which I couldn't find any mention of in the datasheet, unless it does not even require the bootstrap circuitry.
As explained here,
You must drive the MOSFET between its gate and source terminals. Since the source terminal voltage of a high side MOSFET will be
floating, you need a separate voltage supply (VBS: VBoot Strap) for
the gate drive circuit.
I cannot understand how this circuit provides the needed voltage to power the MOSFET.
My first question is: How can this particular driver actually drive the high-side MOSFET?
Followed by: If this requires additional bootstrap circuitry, are there isolated high-side drivers which come with in-built DC-DC converters?
Best Answer
You can use parts in this series with a boot-strap capacitor and diode as shown on page 16 of this datasheet.
http://www.analog.com/media/en/technical-documentation/data-sheets/ADuM3223_4223.pdf
You could also use this part with an isolated power supply such as the ADUM5000.
http://www.analog.com/media/en/technical-documentation/data-sheets/ADuM5000.pdf
Analog devices also makes isolated gate drivers with integrated isolated power such as...
ADUM6132
http://www.analog.com/media/en/technical-documentation/data-sheets/ADuM6132.pdf
ADUM5230
http://www.analog.com/media/en/technical-documentation/data-sheets/ADuM5230.pdf