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Dear,

I try to use IR2110 to drive the mosfet IRF840 and the problem is that as the mosfet is driven by a varying frequency, lets say from 100Hz-50kHz. Someone tell me that as the highside of IR2110 using the boostrap capacitor, so the frequency should be high and suggest me to use the lowside only. However, there is another guy told me that the lowside should be reference to the ground and my mosfet (M9&M10) source reference will be change continuously and it is not grounded definitely.

So i want to ask is that if i can still use IR2110 to drive the mosfet with its lowside or i need to replace it with another model? if then, can u pls give some suggestion.

Moreover, I need to find voltage transducer rated about 200-300V, 400-600W. But it is quite expensive, it cost a US$70 each. Is there anyone know there is a cheaper one in the market.

Thx for help!!

Yes the M9 and M10 not have S to ground so they can't be command directly.
But the IR2110 or 2181 can be used for command low and high transistors even if frequency is low because the MOS gate will sink only a short current pulse from capacitor, after that capacitor will be discharged only by current loses in MOS gate and IR21xx.
A better method to command the high MOSs(and low as well for symetry)is to use a pulse transformer, but usually this type of drive circuit is more complex that usage of IR21xx.