GaN Heads to Space! VPT Introduces Radiation-Hardened DC-DC Converters Featuring GaN Technology

VPT's new DC-DC converter series aims to bring radiation-hardened GaN devices into space applications.

VPT released its SGRB series of gallium nitride-based, radiation hardened, space qualified DC-DC converters at the Satellite 2019 Show.

Gallium nitride (GaN) wide bandgap semiconductors are becoming the go-to choice in commercial applications. GaN in general features low gate and switching losses, as well as lower output and gate capacitance. These GaN characteristics afford members of the SGRB series up to 95% efficiency. 

VPT has now literally boosted this technology into orbit with the introduction of its new SGRB series.

 

The SGRB series of space-qualified, GaN-based DC-DC converters. Image from VPT

 

These DC-DC converters feature a fixed-frequency, reduced voltage switching topology. According to VPT, this allows the converters very low input and output noise, something that becomes crucial when being used in telecommunication systems.

Tough Enough to Withstand the Rigors of Space

As described by Malcolm Campbell, VPT's Executive Director of International Sales and Marketing said. "The SGRB product specifications are particularly well suited for space-borne telecommunication applications where high efficiency, low noise, and radiation tolerance are critical to mission success. Further, we see the design topology of the SGRB as the beginning of an exciting family of future models based on GaN technology."

 

Space-Level Characterizations Include:

• Guaranteed TID performance to 100 krad(Si) including Enhanced Low Dose Rate Sensitivity (ELDRS)
• Single Effects Effects (SEE) performance to 85 MeV/mg/cm2. Transients are fully characterized for cross section and magnitude.

 

Important Compliances and Certification Include:

• Manufactured in a facility certified to ISO9001, J-STD-001 and IPC-A-610
• Designed in line with MIL-HDBK-1547
• Screening up to level T is available

Electrical Characteristics

As noted by Jeremy Ferrell, VPT's Director of Engineering. "The SGRB product uses GaN technology that allows us to increase the efficiency beyond the traditional radiation hardened silicon offering." It is possible to connect up to five of the units in parallel.

 

Block diagram for the SGRB series DC-DC converters. Image from VPT

Highlighted Features

• High efficiency (up to 95%) using GaN technology
• Integrated EMI filter
• 100 V input
• 28 V, 400 W output
• Temperature range: -35°C to 85°C
• 120 V, 10 msec transient
• 80 V, 10 msec transient
• Overvoltage protection
• Output current limit protection
• Output short circuit protection
• Input current telemetry

The first member of the series, now available, is the SGRB10028S DC-DC converter.

Around the Industry

VPT claims that it is "currently the only supplier able to offer products designed and manufactured in accordance with Aerospace Corporation’s TOR requirements.” These include VPT’s SVR and SV series, which don’t mention the use of GaN semiconductors.

However, there are many companies offering DC-DC converters that are in other ways touted as being suitable for space-based deployment.

Additionally, wide bandgap semiconductors such as the GaN devices employed by VPT, as well as silicon carbide (SiC) devices are now being hardened for use in the space environment.

It appears that VPT may well be the only manufacturer, at this time, that has put all the pieces of the puzzle together and can offer a space hardened DC-DC converter that offers the significant advantages of GaN semiconductors.