The ISL73040SEH is a low-side driver designed to drive enhancement mode Gallium Nitride (GaN) FETs in isolated topologies and boost-type configurations. The device has a 4.5V gate drive voltage (VDRV) generated using an internal regulator, which prevents the gate voltage from exceeding the maximum gate-source rating of enhancement mode GaN FETs. The gate drive voltage also features an undervoltage lockout (UVLO) protection that ignores the inputs (IN/INB) and keeps OUTL turned on to ensure the GaN FET is in an OFF state whenever VDRV is below the UVLO threshold. The ISL73040SEH's input can withstand voltages up to 14.7V regardless of the VDD voltage, allowing it to be connected directly to most PWM controllers. The ISL73040SEH's split outputs offer the flexibility to adjust the turn-on and turn-off speed independently by adding additional impedance to the turn-on/off paths. The device operates across the military temperature range from -55°C to +125°C and is offered in an 8 Ld hermetically sealed ceramic Surface Mount Device (SMD) package or die form.