STMicroelectronics Unveils its STi2GaN Portfolio

STMicrolelectroncs’ (ST) new STi²GaN family incorporates the power stage along with the drivers and protection circuitry all in GaN, enabling operation in the MHz range. 

STi²GaN family Image courtesy of ST

 

The family also takes advantage of ST’s bond-wire-free packaging technology to minimize parasitic elements and to improve thermal dissipation. ST is also pioneering a broad range of System-in-Package solutions based on STi²GaN technology, often employing silicon circuitry for logic control.

“STi²GaN continues ST’s long success story in compound materials and Smart Power product innovation, targeting mainly automotive applications and the needs of high-density, high-reliability and high-power. Initial offering of STi²GaN solutions suit On-Board Chargers, LiDAR for autonomous driving, bidirectional DC-DC converters, Class-D amplifiers and power conversion systems,” said Alfio Russo, Group VP and GM Low Voltage and STi²GaN Solutions Macro Division, STMicroelectronics. “The new product family aims to leverage the high-power density and efficiency of GaN to offer an industry-unique range of devices in 100V and 650V clusters that ensure scalability, compactness, and outstanding performance.” 

 

The Advantages of Gallium Nitride

The very useful diagram below summarizes the capabilities of the relevant semiconductor technologies.

Modified image courtesy of ST Video

 

Note the two high bandgap technologies, silicon carbide (SIC) and gallium nitride (GaN). While SiC can handle far more power, GaN can handle up to 10KW, enough for many automotive applications. And, GaN can switch far faster. This means that it will require less filtering, which means less space, less weight and less heat generated. These are all strong pluses for automotive applications.

 

The STi2GaN Portfolio

ST details two clusters of its present and future STi2GaN family. One cluster includes two 100 volt systems-in-packages (SIP) as well as one monolithic implementation. The other direction features 650 volt pure monolithics.

 

100 Volt Systems

A bidirectional 48V/12V DC/DC Converter SiP features a monolithic GaN half-bridge with silicon-based drivers and control. High side and low side resistances are 2 and 1mΩ, respective. The device can switch at 1 MHz, and 98% efficiency is attained when switching at 500 kHz.

There will also be single and four channel LiDAR laser driver SiPs featuring GaN power stages and silicon-based control. The specification is for 50 amp pulses with 400ps rise times.

There is also a 100 volt 4 x 13mΩ full bridge monolithic device. All GaN, it includes the drivers and  protection features.

 

650 Volt Monolithic Devices

At this point, ST has revealed two directions

There is a large signal (LS) HEMT including both the driver and protection circuitry, with protections for both short circuit and overheating. These units, aimed at on-board charging (OBC) for electric vehicles (EV), feature resistances of 30 and 65 mΩ. The absence of silicon allows for switching speeds of up to 2 MHz, and also enables programmable turn on dV/dt. 

There is also a monolithic LS HEMT that features controller and driver. These units are aimed at auxiliary power supplies. Resistances will range from 190 to 500 mΩ. There is also a PWM controller that enables a programmable duty cycle. There will also be an internal startup network. Another feature here is a low stand-by current. 

 

Applications

• EVs
• Power supplies
• DC/DC converters
• Photovoltaic systems
• Wireless charging
• LiDAR