Isolated Gate Drivers Handle SiC MOSFETs at High Voltages

STMicroelectronics introduced a new series of galvanically isolated gate drivers capable of delivering source and sink currents of up to 3 A.

Both belonging to its STGAP3S family, the new STGAP3S3S series is optimized for silicon carbide (SiC) MOSFETs, while the STGAP3S3IF series is suited to IGBTs, both widely used in charging stations, battery energy-storage systems (BESS), solar inverters, industrial-grade electric vehicles (EVs) such as forklifts, as well as motor drives, pumps, and fans.

The gate drivers in the STGAP3S family support high-voltage rails up to 1200-V in applications such as power-factor correction (PFC), power supply units (PSUs), DC-DC converters, and inverters. ST said its reinforced galvanic isolation protects the power-stage circuitry against transients of up to 9.6 kV and ensures common-mode transient immunity (CMTI) of up to 200 V/ns.

The broader family spans three series capable of sinking/sourcing up to 10A, 6A, and now 3A, each containing variants designed to drive IGBTs and SiC MOSFETs.

The STGAP3S3 devices integrate a complete active Miller clamp, including clamping MOSFET, to prevent unwanted induced turn-on, and the resulting shoot-through currents. This saves PCB space, simplifies the design, and reduces the bill of materials. The 6A STGAP3S6 and 10A STGAP3SX series contain a pre-driver for an external MOSFET, giving extra flexibility to optimize the clamping speed in systems with high gate-drive current.

All STGAP3S drivers have desaturation detection with soft turn-off to ensure controlled voltage and current transitions and have diagnostic pins that indicate when desaturation protection, undervoltage-lockout UVLO, and thermal shutdown are active. The new devcies meet international safety and insulation certifications, including UL 1577 and IEC 60747-17, for robust isolation, safety, and reliability at high voltages, according to ST.

The complete STGAP3S family for driving IGBTs and SiC MOSFETs is in full production. An evaluation board is available for each STGAP3S driver, including the latest 3A models. These two boards, the EVLSTGAP3S3S and EVLSTGAP3S3IF, are half-bridge boards that come with protection already configured and provide test points and diagnostic LEDs to assist development. 

The drivers are offered in the SO16W wide-body package, starting from $1.93 for 1,000-piece orders.