Gallium nitride (GaN) transistors have radiation tolerance that makes them a good fit for a growing variety of space industry applications, and Infineon Technologies just upped its GaN game with the announcement of a new family of radiation-hardened GaN High Electron Mobility Transistors (HEMTs) targeted at applications related to orbiting space vehicles, manned space exploration, and deep space probes, among other use cases.
The new devices are based on Infineon’s CoolGaN technology, and the latest announcement came almost a year to the day after the firm announced CoolGaN.
Sean Darcy, senior director of aerospace and Defense at Infineon, said in a briefing that one of the new radiation-hardened GaN HEMTs is “first in-house manufactured GaN transistor to earn the highest quality certification of reliability assigned by the United States Defense Logistics Agency (DLA) to the Joint Army Navy Space (JANS) Specification MIL-PRF-19500/794.”
Keying in on the in-house manufacturing of the device, Darcy added, “It is important to note that Infineon owns the fab in Europe that manufactures the radiation wafers, and we are not dependent on external foundries to maintain continuity of supply.”
The new GaN-based transistors can be used in combination with traditional silicon MOSFET technology. Josemari Mapa, senior product marketing engineer at Infineon, said that while silicon and gallium arsenide have proven appropriate for a number of space applications at different voltages, GaN has emerged more recently as a viable option thanks “to the wide band gap structure of the material, [which] enables high frequency applications due to high electromobility and also the power density,” in addition to its “rad-hard” properties and high thermal conductivity. They have a Voltage Detection System maximum limit of 100 volts.
The first three product variations in the new radiation-hardened GaN transistor line are 100 V, 52 A devices featuring a drain source on resistance of 4 mΩ (typical) and total gate charge (Qg) of 8.8 nC (typical). Encased in robust, hermetically sealed ceramic surface mount packages, the transistors are Single Event Effect (SEE) hardened up to LET (GaN) = 70 MeV.cm2/mg (Au ion). Two devices, which are not JANS certified, are screened to a Total Ionizing Dose (TID) of 100 krad and 500 krad. The third device, screened to 500 krad TID, is qualified to the rigorous JANS Specification MIL-PRF-19500/794. That JANS-certified device is expected to be released this summer, while the first two transistors are available immediately, Darcy said, adding that all three were also tested internally for radiation hardness.