STMicro Adds 3 A Isolated Gate Drivers for SiC and IGBT Power Stages

STMicroelectronics has put two new 3 A isolated gate-driver families into full production, priced from $1.93 per unit in 1,000-piece orders. The STGAP3S3S series is optimized for silicon carbide MOSFETs. The STGAP3S3IF series targets IGBTs.

Both families belong to ST's STGAP3S line of galvanically isolated gate drivers, capable of sourcing and sinking up to 3 A of gate current. The broader STGAP3S family now spans three current classes: 10 A, 6 A and 3 A. Each class contains variants for IGBTs and for SiC MOSFETs.

The new drivers support high-voltage rails up to 1,200 V. Target applications include power-factor correction stages, power supply units, DC-DC converters and inverters. End products range from EV charging stations and battery energy-storage systems to solar inverters, industrial electric vehicles such as forklifts, motor drives, pumps and fans.

How much isolation do the drivers provide?

ST said its reinforced galvanic isolation protects power-stage circuitry against transients up to 9.6 kV. The parts also guarantee common-mode transient immunity of up to 200 V/ns, a figure that matters in SiC designs where fast switching edges induce parasitic turn-on in conventional drivers.

The devices meet international safety and insulation certifications, including UL 1577 and IEC 60747-17, according to ST. The certifications cover robust isolation, safety and reliability at high voltages.

What protection features are integrated?

The STGAP3S3 devices integrate a complete active Miller clamp, including the clamping MOSFET. The clamp prevents unwanted induced turn-on and the shoot-through currents that follow. Integration saves PCB space, simplifies design and reduces the bill of materials.

The higher-current 6 A STGAP3S6 and 10 A STGAP3SX series take a different approach. They contain a pre-driver for an external MOSFET, giving designers extra flexibility to optimize clamping speed in systems with high gate-drive current.

All STGAP3S drivers include desaturation detection with soft turn-off. This ensures controlled voltage and current transitions during a fault. Diagnostic pins indicate when desaturation protection, undervoltage lockout or thermal shutdown is active.

What development tools ship with the parts?

ST supplies an evaluation board for every STGAP3S driver, including the two latest 3 A models. The EVLSTGAP3S3S board serves the SiC-optimized variant. The EVLSTGAP3S3IF board serves the IGBT variant.

Both boards are half-bridge designs with protection circuitry already configured. They provide test points and diagnostic LEDs to assist development.

The drivers ship in the SO16W wide-body package.

Why the 3 A class matters

The 3 A addition extends ST's isolated driver portfolio down into the mid-power segment, where SiC MOSFETs and IGBTs with modest gate-charge requirements dominate charging infrastructure, storage converters and industrial motion systems. The complete STGAP3S family for both switch technologies is in volume production now, and the $1.93 entry price signals ST's intent to defend share in high-volume industrial and energy applications as SiC adoption broadens.