STMicroelectronics’ Debuts Isolated Gate Driver Aimed at SiC MOSFETS

STMicroelectronics’ (ST) STGAP2SiCSN is available in two versions, one with separate outputs, allowing for the optimization of MOSFET turn-on and turn-off times. 

Configuration of the STGAP2SiCSN with separate outputs. Image courtesy of datasheet

There is also a single-output version with an active Miller clamp function. This configuration employs the Miller clamp to limit excessive oscillation of the power MOSFET, improving stability in hard-switching applications.

 

The version featuring a single output and Miller clamp. Image courtesy of datasheet

As illustrated in the diagrams above, both versions feature dual control logic input pins. This allows for a choice of the control signal polarity. It also allows for the implementation of HW interlocking protection to guard against cross-conduction in the event of a controller malfunction.

Basic Facts

The STGAP2SiCSN offers galvanic isolation between the low-voltage control circuitry and the gate-driving channel and functions with a high-voltage rail of up to 1700V. The control circuitry’s logic inputs can operate at TTL and CMOS levels down to 3.3V, making it easy to control the unit directly from a DSP or MCU.

High PWM accuracy is assured by the device’s less than 75ns input-to-output propagation time. The common-mode transient immunity (CMTI) over the driver’s full temperature range is ±100V/ns. To reduce power consumption when idle, the unit features a standby mode.

Protections

Under-voltage lockout (UVLO) is threshold tuned in a manner as to not allow the power MOSFETs to be driven to operate in unsafe or inefficient conditions. In the event of junction overheating, built-in thermal protection forces the driver into a temporary “safe state”. Normal functioning resumes as soon junction temperature returns to a safe level.

Further Specifications

• Thermal Resistance, junction to ambient is 123℃/W
• Maximum switching frequency is 1 MHz
• Logic supply voltage range is 3.1V to 5.5V
• Minimum output pulse width is 100nS
• Gate driver voltage:
  • Typical turn on is 15.5V
  • Typical turn off is 14.8V

Applications

• EV charging systems
• Switched-mode power supplies (SMPS)
• DC/DC converters
• Uninterruptible power supplies (UPS)
• High-voltage power-factor correction (PFC)
• Solar power applications, such as 600/1200 V inverters
• Motor drives
• Factory automation
• Fans
• Induction heating
• Home appliances

Safety

• ESD, human body model (HBM) is 2kV

Physical Considerations

• The STGAP2SiCSN is available an S0-8N package with dimensions of 5mm x 4mm
• The driver’s recommended junction temperature operating range is from -40 to +125°C, with an absolute maximum of specified at 150°C

Getting to Market Faster

ST offers two evaluation boards, one for each version of the STGAP2SICSN: 

• The EVSTGAP2SICSN is a half-bridge evaluation board aimed at aiding engineers to evaluate and to familiarize themselves with the STGAP2SICSN isolated single gate driver. The board puts the STGAP2SICSN through its paces while driving a half-bridge power stage at voltages of up to 520V.
• The EVSTGAP2SICSNC is a half-bridge evaluation board for the STGAP2SICSNC isolated single gate driver. This is the Miller clamp version. It also drives a half-bridge power stage with voltages as high as 520V.