Isolated SiC gate drivers save space in narrow SO-8 package
Single-channel gate drivers from STMicroelectronics are packaged in a narrow body SO-8 package to save space. The STGap2SiCSN is optimised to control SiC MOSFETs and is claimed to deliver robust performance with pulse width modulation (PWM) control.
SiC technology is becoming widely adopted to boost power conversion efficiency and ST claims the STGAP2SiCSN contributes to this adoption by simplifying design, as well as saving space in energy-conscious power systems, drives, and controls. Applications include electric vehicle charging systems, switched mode power supplies, high voltage power factor correction (PFC), DC/DC converters, uninterruptible power supplies (UPS), solar power, motor drives, fans, factory automation, home appliances, and induction heating.
The gate drivers feature galvanic isolation between the gate driving channel and the low voltage control. They operate with up to 1700V on the high voltage rail. The input to output propagation time of less than 75ns ensures high PWM accuracy, and there is reliable switching due to common mode transient immunity (CMTI) of ±100V/ns, according to the company. Built-in protection includes under-voltage lockout (UVLO), with a threshold tuned to prevent SiC power switches from operating in low efficiency or unsafe conditions. Thermal shutdown turns both driver outputs low if excessive junction temperature is detected.
There are two configurations are available, giving a choice of separate outputs that allow turn on and turn off times to be independently optimised using an external resistor or a single output with active Miller clamp function. The single output configuration enhances stability in high-frequency hard-switching applications, leveraging the Miller clamp to prevent excessive oscillation of the power switch, explains ST.
The STGAP2SiCSN logic inputs are compatible with TTL and CMOS logic down to 3.3V, simplifying connection to a host microcontroller or DSP. The driver can sink and source up to 4.0A at gate-driving voltage up to 26V. An integrated bootstrap diode simplifies design and enhances reliability, and a shutdown mode with separate input pin helps minimise system power consumption.
The STGAP2SiCSN is available now, in the 5.0 x 4.0mm-wide SO-8N package.
