The space-qualified GaN power transistors, driver ICs and modules of Freebird Semiconductor will now be available from EPC Space, a new company which includes Freebird and its assets, and is a joint-venture between GaN power transistor maker EPC and high-rel power supply company VPT.

None of those concerned are revealing the exact nature of the deals involved.

The radiation-hardened product range will have “some enhancements but mainly the same products as before”, EPC told Electronics Weekly – see tables below.

“The joint venture – EPC Space – is taking the superior performance of gallium nitride to the high reliability community,” said EPC founder and CEO Alex Lidow, “VPT’s power conversion solutions for avionics, military, and space applications is the perfect complement to EPC’s GaN-based power conversion devices.”

Target applications include space-borne power supplies for lidar, motor drives and ion thrusters.

“GaN technology enables a new generation of power converters in space operating at higher frequencies, higher efficiencies, and greater power densities than ever achievable before,” claimed VPT founder and CEO Dan Sable.

GaN-on-silicon is the underlying technology, includign some or all of the ICs – Freebird used the phrase “GaN driving GaN technology”.

Electronics Weekly asked EPC why GaN power components should be chosen over traditional rad-hard silicon, silicon-on-insulator or silicon-on-sapphire parts.

GaN is superior to silicon-on-insulator and to silicon-on-sapphire for two reasons:

First, GaN transistors do not have an insulating gate oxide under the gate electrode.

It is this gate oxide in a silicon mosfets that traps positive charges from the gamma radiation. These positive changes trapped in the gate oxide will eventually cause the silicon mosfet to become depletion mode. At this point the device is normally on.  That never occurs in a GaN transistor from EPC Space.

The second reason is that EPC Space GaN transistors are not susceptible to two main failure mechanisms when exposed to heavy ions: single event gate rupture (SEGR) or single event upset (SEU). SEGR doesn’t happen because GaN transistors from EPC Space do not have a gate oxide that can rupture. SEU doesn’t happen because our GaN devices do not generate a minority carrier cloud that causes a momentary short circuit in silicon.

The parts are rated for total incident dose (TID) >40Mrad and a single event effect (SEE) linear energy transfer (LET) of 85MeVcm2/mg, suiting them, according to the company, to all space environment and orbits: deep space, LEO, MEO and GEO.

“These devices are SEE-immune and are fully screened and certified to space level requirements. They are a different design, different process, and have a different starting material compared with [EPC’s] standard commercial product,” EPC told Electronics Weekly.

As for the foundry used for the space parts, EPC would only reveal that it is in Taiwan.

As GaN allows faster switching, do faster switching edges provide unique challenges to the designer creating space-based power supplies?

“Faster switching allows designers to shrink the size and weight of their space-based systems,” said EPC. “Many people have the misconception that faster switching might generate more EMI or EMC that could interfere with other parts of the systems. In fact, faster switching moves the generated EMI and EMC to higher frequencies that are easier to filter.”

Freebird Semiconductor discretes, ICs and modules that are now EPC Space products: