Texas Instruments (TI) has introduced a new family of radiation-hardened and radiation-tolerant GaN FET gate drivers, designed to improve power system efficiency for space satellites. According to TI, the newly launched drivers are capable of supporting voltages ranging from 22-200 V, making them the first space-grade GaN FET gate drivers that can operate at up to 200 V.  

Javier Valle, product line manager of space power products at TI, mentioned during an exclusive conversation with EE Times how the need for more on-orbit processing capabilities, more precise imagery and augmented data transmission are on the rise. To meet these requirements, engineers have been focusing on power system efficiency.

To address customer needs, the new radiation-hardened GaN FET drivers arrive in a flexible family with a large voltage range. Covering a broad spectrum of satellite power systems, this includes drivers rated at 22 V, 60 V and 200 V. Suited for low, medium and geosynchronous earth orbits for all types of space mission requirements, the 200 V GaN GET gate driver can be used for the solar panel input power conversion while the 60 V and 22 V variations can be used for the satellite’s electrical system power distribution all the way to point of load regulation.

TI’s GaN FET gate drivers are designed to enhance performance by enabling faster rise and fall times for GaN FETs. This improvement reduces the size and weight of power supplies, thus enhancing power system efficiency and allowing satellites to better utilize the energy generated by their solar cells for mission-critical functions.

“Space has changed drastically in recent years; it’s not only about conventional space missions now. Whether the mission requires radiation tolerant products or more extreme radiation hardened products for deep-space exploration, our drivers are meant to support all radiation requirement levels,” Valle said.

TI’s family of space-grade GaN FET gate drivers include radiation-hardened QML Class P and Class V products in plastic and ceramic packages, respectively, as well as radiation-tolerant Space Enhanced Plastic (SEP) products. QML products, in both ceramic and plastic packages, for the GaN FET gate drivers provide options for missions with higher radiation and reliability requirements. SEP products are a great option for lower orbit missions where there is less radiation exposure (Figure 1).

Satellite power systems

The technologies running satellites are changing as the demands for space operations rise. Traditionally, conventional silicon-based technologies have been used to build satellite power systems; yet, as space missions change and power demands grow, GaN technology is becoming increasingly attractive. Modern satellite applications would find GaN transistors ideal since they provide superior efficiency, higher power density and dependability.

However, driving these GaN FETs requires specialized gate drivers.As the need for higher power output and efficiency in space applications grows, TI’s new radiation-hardened GaN FET gate drivers are positioned to fill a crucial gap in the market. These drivers are suitable for both low-power and high-power space applications, from small satellite systems to larger and all types of mission requirements.

“By introducing this new family of GaN FET gate drivers, we are providing customers with the flexibility they need to address the wide variety of power requirements across different satellite missions,” Valle said. “Our goal is to enable the development of more efficient and reliable power systems for both traditional space applications and cutting-edge missions such as satellite constellations and deep-space exploration.”

Making sure components can resist the hostile radiation environment is one of the most important difficulties in building power systems for space. To guarantee these GaN FET gate drivers endure space, TI has developed them using multiple radiation-hardened techniques. Valle claimed that for the most demanding space missions, the drivers are designed to survive total ionizing dose (TID) exposure of up to 100 krad(Si). Hence, they meet the need for satellite power systems in low Earth orbit (LEO), as well as deep-space missions.

“It is the radiation-hardened process that we use,” Valle explained. “We cover the a wide range for TID requirements from 20 krad(Si) to 100 krad(Si), and we also have a wide rating for heavy ions exposure, up to Linear Energy Transfer (LET) of 43 MeV-cm²/mg, which is ideal for LEO applications, extending all the way to 75 MeV-cm²/mg for deep-space missions.” This robust radiation tolerance ensures that the GaN FET gate drivers retain their functionality and efficiency, even under the most extreme conditions in space.

Valle added that “these drivers are not just rated for radiation-hardened or radiation tolerant environments but engineered to excel in all space conditions, offering reliability and long-term durability in challenging missions.”

Boosting efficiency and reducing size

One main benefit of GaN technology is its capacity to operate at higher switching frequencies, hence improving power density. Often constrained by multiple factors, traditional space power systems run at lower frequencies, which results in larger passive components. By comparison, TI’s GaN FET gate drivers can support switching frequencies of up to 5 MHz, which permits smaller passive components and higher power density.

“Our GaN FET gate drivers allow notable decreases in the size of the passive components needed for power conversion by running at higher switching frequencies,” Valle said. “This not only helps save valuable space on a satellite but also, due to the inherent benefits of GaN FETs, it lowers the heat generated in the process—an important factor in space—where normal heat dissipation methods aren’t available.”

For satellites, where power is limited and thermal control is a continuous challenge, power conversion efficiency becomes a major issue. By reaching efficiency levels greater than 90%, TI’s GaN FET gate drivers help to solve this problem by improving conventional systems usually running in the 70-80% efficiency range.

“We are moving from traditional satellite power systems, which have efficiency rates in the range of 70-80% to systems that can achieve greater than 90% efficiency,” Valle said. “This leap forward is vital for meeting the rising power needs of modern satellites, which require compact and high-performance systems to handle more complex missions.”

Valle also covered inductive parasitics, which can generate problems for high-performance systems.

“Inductive parasitics are one of the challenges we face, especially when it comes to high frequency and high-power applications,” he added. “We have focused on reducing these parasitics, hence the arrangement and packaging of our products are really crucial. We minimize these parasitic effects through our design and packaging process, therefore assuring that the drivers continue to be highly efficient and enable low system losses.”

Unwanted voltage spikes and higher losses might result from inductive parasitics not under control.

“Our products are designed with this in mind, using cutting-edge technologies to minimize these parasitics. This helps to preserve system integrity, especially in high-frequency applications where these effects become especially more noticeable,” Valle said. This deliberate focus on layout, package and design ensures that the GaN FET gate drivers enable high efficiency power systems.

Another important problem in space applications is thermal management since the absence of a conductive medium like air makes heat dissipation more challenging. TI’s GaN FET gate drivers include large thermal pads on the bottom of the products to remove heat from the package, therefore assuring the correct operation of components in the space environment. Furthermore, less power dissipation is produced by GaN FETs than by silicon-based alternatives, which improves power conversion efficiency and lowers the thermal load on the satellite’s whole system (Figure 2).

Flexibility and customization for satellite missions

TI’s GaN FET gate drivers enable system flexibility. Pulse width modulation and dead time control are some of the features users can leverage to enable the usage of complex topologies like zero voltage switching converters. This capacity lowers power losses and helps to increase general system efficiency, hence improving performance for space missions.

As the space industry continues to evolve, GaN FET drivers will play a crucial role in the development of next-generation power systems.

“Looking ahead, we are excited about the future of space exploration, and we believe our new GaN FET gate drivers will be instrumental in supporting the power needs of the next generation of satellites and space systems,” Valle said. “With this innovation, TI is not just meeting the needs of today’s missions but also paving the way for the more ambitious space projects of tomorrow.”

From EEtimes