[moved] Will this bootstrapping capacitor work?

[electrochamp]

Hello
In the figure attached below if h Bridge is connected to isolated power supply of 300 volts will the high side mosfet work or not? (as voltage at gate must be around 10volts greater than the drain voltage and in isolated ground our bridge ground will be different so how boot strapping capacitor will get charge to provide 310 volts?)
secondly if i use non isolated topology then my circuit might not work properly? or it will blew away?
#Tahmid

 

[KlausST]

Hi,

I can't find isolated ground. All grounds are common.

The bootstrap capacitor works. The circuit is correct.
Don't forget to use a bulk capacitor and a ceramic capacitor (paralleled) at each driver 12V supply connection.

I personally like higher ohmic resistors on GS of each mosfet.

Klaus

 

[treez]

it looks ok but those bootstrap circuits can be bad if the fet vds transitions at more than 50v/ns....gate drive txfmr is better

 

[electrochamp]

Hi,

I can't find isolated ground. All grounds are common.

The bootstrap capacitor works. The circuit is correct.
Don't forget to use a bulk capacitor and a ceramic capacitor (paralleled) at each driver 12V supply connection.

I personally like higher ohmic resistors on GS of each mosfet.

Klaus

thanks Klaus;
if a seprate power supply is used for bridge i-e +300 to high side drain and ground to low side mosfet source and this ground of power supply(Bridge) is not common with driver circuit, in this case will ground get isolated? for the same case isolated ground will this circuit work?

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thanks Klaus;
if two different supplies are used 1)Supply of 12V for driver circuit and 2)Battery followed by push pull for bridge both of the supplies didn't have common ground then this circuit will work or not?

 

[KlausST]

Hi,

Please draw a schematic with your ideas to clarify this.

Usually you can not split driver GND and power GND...But show us...

Klaus

 

[electrochamp]

Ok i will try to upload my idea thanks