1.5 A gate drive with 5 kV isolation — the timing and noise-rejection specs that matter
The FOD3150 is a single-channel optocoupler gate driver from onsemi, delivering 1.5 A peak output current sourced from a 15 V to 30 V supply rail — enough to drive the gate capacitance of medium-power IGBTs and MOSFETs in inverter legs without an external booster stage. Its 5000 Vrms isolation rating, paired with a minimum common-mode transient immunity of 20 kV/µs, means the output side can float at the high-side switch potential while rejecting the fast dv/dt edges from a PWM switching node — the CMTI figure is the one that prevents false turn-on in a motor-drive half-bridge. Propagation delay is 500 ns max (tpLH and tpHL symmetrical), with a pulse-width distortion ceiling of 300 ns — these timing numbers set the dead-time budget in the controller firmware; a 500 ns delay at each edge means the complementary switch must wait at least 1 µs before turning on, or shoot-through current burns the bridge.
The FOD3150 is specified over -40°C to +100°C operating temperature, which covers the industrial enclosure ambient and the self-heating inside a crowded power supply — the 60 ns typical rise and fall times hold across this band, so the gate charge delivery rate does not degrade at the hot corner. Output high and low drive currents are rated 1 A each, meaning the device can both source and sink 1 A into the gate — this symmetric drive avoids the slow turn-off that plagues single-ended drivers when the IGBT's Miller plateau holds the gate voltage. The LED forward voltage is 1.5 V typical, with a maximum DC forward current of 25 mA — the input-side resistor should be sized to deliver 10-15 mA at the logic supply voltage, leaving headroom for LED ageing without exceeding the 25 mA ceiling.