I'm looking for a optocoupler ,which can turn on and turn of about 30kHz . There will be a mosfet at its output. Opto's supply voltage will around 12-24V. Also switching signal is from opamp's output, so signal current will be low. Any suggestion please ???
That MOSFET has a large gate input capacitance of 12,000pF and requires the transfer of 236nC of charge to turn it on and off, so you will need a low-impedance gate driver at the output of the opto to operate at 30kHz.
For example,, to achieve a rise/fall time of 1us will require a driver that can source and sink 230mA of current during that transition time.
That MOSFET has a large gate input capacitance of 12,000pF and requires the transfer of 236nC of charge to turn it on and off, so you will need a low-impedance gate driver at the output of the opto to operate at 30kHz.
For example,, to achieve a rise/fall time of 1us will require a driver that can source and sink 230mA of current during that transition time.