An optically isolated N-channel MOSFET driver (10) turns on a MOSFET device (72) in response to an optical input signal to drive a load (74). The turn-on time of the MOSFET is enhanced by a current boost circuit (34). As the MOSFET transcends to an on state and delivers current to the load, the voltage across the device diminishes and causes the current boost circuit to become inactive thus reducing to zero the current drain consumed by the current boost circuit. A photovoltaic array (40) maintains the MOSFET operation. An optically isolated SCR (66) is respondent to the absence of a light signal to turn off the MOSFET. Furthermore, the optical decoupling of the SCR, between the gate and source of the MOSFET device, is arranged to provide enhanced noise immunity. A voltage clamping circuit (70) coupled between the gate and source of the MOSFET device provides additional protection to the device from large over voltages.
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