Isolated Gate Drivers Offer Flexible Protection for Mid-Power Switches
STMicroelectronics’ STGAP3S family of gate drivers for silicon-carbide (SiC) and IGBT power switches combines the company's latest robust galvanic-isolation technology with optimized desaturation protection and a flexible Miller-clamp architecture. Targeting mid-power consumer and industrial products involving motor drives and energy-conversion systems, the devices help enhance products’ reliability and longevity, even under the harshest operating conditions.
Thanks to its reinforced capacitive galvanic isolation between the gate-driving channel and the low-voltage control and interface circuitry, the STGAP3S is rated to withstand 9.6-kV transient isolation voltage (VIOTM) with 200-V/ns common-mode transient immunity (CMTI).
Panoply of Protection Features
The drivers’ integrated desaturation protection implements overload and short-circuit protection for an external power switch, which enables designers to adjust the turn-off strategy using an external resistor to optimize the protection turn-off speed while avoiding excessive overvoltage spikes. The undervoltage-lockout (UVLO) protection prevents turn-on with insufficient drive voltage.
Additional protection is provided by driver’s on-chip Miller Clamp architecture, which includes a pre-driver for an external N-channel MOSFET. This enables designers to adjust the clamp’s intervention speed to best prevent induced turn-on and suppress cross-conduction.
The drivers also provide a UVLO/desaturation fault indicator signal, plus a second overtemperature fault signal via two dedicated open-drain diagnostic pins.
By providing state-of-the-art isolation and protection, the driver IC enhances reliability in motor drives for industrial applications such as air conditioning, factory automation, and home appliances. The new drivers are also used in power and energy applications, including charging stations, energy storage systems, power factor correction (PFC), DC-DC converters, and solar inverters.
The STGAP3S family includes different options with 10- and 6-A current capability, each of them available with differentiated UVLO and desaturation intervention thresholds. This helps designers select the best device to match the performance of either SiC MOSFET or IGBT power devices.
The STGAP3SXS is in production now, in the SO-16W wide-body package, from $2.34 for orders of 1,000 pieces.
