Isolated Gate Driver That Safely Controls SiC MOSFETs

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Turns off to prevent excessive dissipation and includes built-in protection that prevents cycle distortion and minimises energy losses

For safe control of silicon carbide (SiC) MOSFETs while operating from a high-voltage rail up to 1200V is the newly launched isolated gate driver, the STGAP2SiCS.

It is capable of producing a gate-driving voltage of up to 26V and has a raised Under-Voltage Lockout (UVLO) threshold of 15.5V to meet the turn-on requirements of SiC MOSFETs. If the driving voltage is too low (due to low supply voltage), then the UVLO turns off the MOSFET to prevent excessive dissipation. The driver features dual input pins that let designers determine the gate-drive signal polarity.

With 6kV of galvanic isolation between the input section and the gate-driving output, the STGAP2SiCS ensures safety in consumer and industrial applications. Its 4A output-sink/source capability suits mid- and high-power convertors, power supplies and inverters in equipment such as high-end home appliances, industrial drives, fans, induction heaters, welders and UPSes.

The standby mode feature of the STGAP2SiCS cuts system power consumption, as well as built-in protection including hardware interlocks prevents cross conduction and thermal shutdown of both the low-voltage section and the high-voltage driving channel. Matched propagation delays between the low-voltage and high-voltage sections prevent cycle distortion and minimise energy losses. The total delay is less than 75ns that permits accurate pulse-width modulation (PWM) control up to high switching frequencies.

Two different output configurations are available: One with separate output pins for independent optimisation of turn-on and turn-off times using a dedicated gate resistor. The second has high-frequency hard switching, with a single output pin and active Miller clamp that limits oscillation of the SiC MOSFET gate-source voltage to prevent unwanted turn-on and enhance reliability. The input circuitry is compatible with CMOS/TTL logic down to 3.3V, which allows easy interfacing with a wide variety of control ICs.

Housed in a wide-body SO-8W package that ensures 8mm creepage within a compact footprint, the STGAP2SiCS is now available from STMicroelectronics.


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