IRS2184 high side only dirving issue ?

Hi,

I'm trying to use IRS2184s high side driving section to switch a buck converter. But the output of the high side driver is not continuous. It comes and goes. I left the low side drive pin floating. could this be the reason ? I shorted that pin to the Vs or the floating point and it works but will there be any problem in using the chip that way ? Is there a proper way to do it ?
Please reply !

Thanks,
Sandi