STMicroelectronics’ New Isolated Gate Driver is Aimed At SiC MOSFETS

The STGAP2SICS from STMicroelectronics (ST) is a single gate, 4 amp SiC MOSFET driver that features a full 6kV of galvanic isolation, separating the low voltage control and interface section from the powerful gate driving channel.

 

The STGAP2SiC. Image courtesy of ST

 

Driving and Controlling SiC MOSFETS

The STGAP2SiCS can provide up to 26 volts, but if output goes below 15.5 volts, the unit’s under-voltage lockout (UVLO) will cause the MOSFET to shut down. Whether or not the low driving voltage is caused by a low power supply voltage, this valuable feature will prevent excessive dissipation.

The unit’s input is compatible with CMOS/TTL logic levels as low as 3.3 volts. This serves to allow easy interfacing with industry standard control ICs. 

 

Two Distinct Output Configurations

The first configuration, available as model number STGAP2SICSCTR, is suited to high-frequency hard switching. It features a single output pin and an active Miller clamp. This limits the oscillation of the SiC MOSFET gate-source voltage, preventing unwanted turn-on and serving to enhance reliability. 

 

The STGAP2SiCS gate driving channel in its single output with Miller clamp mode. Image courtesy of ST’s datasheet

 

The second configuration, available as model STGAP2SICSTR, features separate output pins allowing for independent optimization of turn-on and turn-off times through the employment of dedicated gate resistors. 

 

The STGAP2SiCS’s gate driving channel in separate output mode.  Image courtesy of datasheet

 

Here, GON and GOFF are source and sink outputs, respectively.

 

Features and Specifications of the STGAP2SiCS

On the input side, dual input pins allow designers to determine the gate-drive signal polarity. A standby mode is available to reduce power consumption when the driver is idle.

 

Absolute Maximums

• The maximum voltage supplying the control and interface section is 6.5 volts

• The maximum voltage that the inputs to the control and interface section can tolerate is also 6.5 volts

• The maximum powers supply voltage for the gate driving section is 28 volts

 

Recommended Operating Voltages

• For the control and interface section, ST recommends 5.5 volts for both power supply and data inputs

• For the gate driving section, 26 volts is recommended 

• Maximums switching speed is 1 MHz
• Output pulse width: 100 nanoseconds

 

Thermal Data

Thermal resistance, junction to ambient (RTH(JA)): 118 °C/W

 

Standby

• Standby Time: 200 μs (typ)
• Wake-up time: 20 μs (typ)
• Wake-up delay:140 μs (typ)
• Standby filter: 280 μs (typ)

 

Applications

The STGAP2SiCS’ 4A output-sink/source capability suits it for use in:

• Power convertors
• Power supplies
• Inverters 
• Industrial drives
• Induction heaters
• Welding
• Fans
• Home appliances

 

Physical Considerations

• The driver is available in an SO-8W package, maximum dimensions of 6.05 by 10.52 mm (including gull wings)
• Operation is over a -40 to +150℃ temperature range

 

Regulatory and Safety Features

• Electrostatic discharge (ESD) protection, human body model (HBM), is 2 kilovolts 
• The device features 8 mm of creepage, measured from input to output terminals