What the FOD8343 does in a drive stage
The FOD8343 is a single-channel optocoupler gate driver from onsemi, built with optical coupling technology. It delivers 4 A peak output current to drive IGBTs and power MOSFETs in motor drives, inverters, and industrial power supplies. The 5000 Vrms isolation rating provides reinforced galvanic separation between the low-voltage controller side and the high-voltage power stage, meeting safety requirements for equipment with working voltages up to several hundred volts. The output supply range of 10 V to 30 V covers the typical gate drive voltages for IGBTs (15 V) and standard MOSFETs (10–12 V), with headroom for desaturation protection circuits that need a higher bias.
Isolation and transient immunity — what the numbers mean for your BOM
The 5000 Vrms isolation is a 1-minute hipot rating per UL 1577. For a 400 VDC bus inverter, this provides a 12.5× safety margin on the peak repetitive voltage, which is comfortable for reinforced insulation in IEC 61800-5-1 motor-drive applications. The 50 kV/µs minimum common-mode transient immunity means the output state does not glitch when the power stage switches at dv/dt rates typical of SiC and fast IGBTs — a spec that matters more than raw isolation voltage in a noisy inverter layout. Pulse width distortion is held to 65 ns max, and propagation delay is matched at 210 ns max for both rising and falling edges. This symmetry keeps the duty-cycle error below 0.1% at 20 kHz switching, so the FOD8343 does not introduce significant dead-time asymmetry that would need software compensation.
Package and footprint considerations
Housed in a 6-SOIC (0.268", 6.80 mm Width) surface-mount package with a 6-SOP supplier device package designation. The 6-pin SOIC-6 footprint is shared with several other optocoupler gate drivers, making the FOD8343 a drop-in candidate for existing layouts designed for the industry-standard footprint.