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Thousands of satellites circle our planet, many relying on TI space-qualified electronics to monitor changes in climate and oceans, improve farm yields, and provide us with communications, navigation, and other scientific data.
Resources
- Choose the Right Devices for Your Design and Optimize Costs
- Setting a New Space Industry Standard with QML-P
- Space-Enhanced Products Addressing Challenges in LEO Applications
Space, however, is the most unforgiving of all operating environments. The harsh environment requires that the electronic components used in making satellites must withstand a wide variety of challenges ranging from hundreds of degrees of temperature change to massive amounts of radiation. Added to the mix is an expectation of flawless functioning for decades, usually without the possibility of upgrades or performance tweaks.
Outside the protective cover of the Earth’s atmosphere, the solar system is filled with radiation that can damage electronic devices. The effects range from performance degradation to complete functional failure.
Most Components and Materials Not Made for Space
These harsh conditions mean that commercial off-the-shelf (COTS) components can’t be used for space missions. Some space programs have investigated using automotive-grade AEC-Q100 products with more stringent qualification requirements added. However, the extra qualification steps in Q100 parts still don’t meet all of the necessities of a space application.
Thus, there are strict limits on materials that can be used in space, which may endure phenomena such as outgassing. Outgassing is a process whereby the harsh temperature and vacuum conditions of space vaporize organic compounds from materials like plastic, glues, and adhesives, and then they’re deposited onto electronics, causing them to fail.
What’s more, substances such as cadmium and zinc will disintegrate in low pressures, and other metals like tin will develop metallic whiskers—called dendrites—that could bridge electrical connections and induce shorts and component failures.
Tin whiskers are electrically conductive, crystalline structures that sometimes grow from surfaces where tin is used as a final finish. To counteract this possibility, finishes on spacecraft components are either nickel-palladium-gold or 63% tin/37% lead to reduce the risk of tin-whisker-induced failures.
Device Selection for the Mission at Hand
To enable shorter development times, Texas Instruments’ Space EP products provide extensive radiation characterization to meet the requirements of space missions (Fig. 1).
Some of the considerations that Space EP products address include:
- Two products using the same process technology or node might have totally different radiation responses due to how the product is designed and which modules in the process are used. TI manufactures each Space EP device at a single fabrication facility, assembly site, and test site to control site-to-site variations between material radiation tolerance and electrical specifications. Using only one production flow, one wafer fab, and one assembly site for each product greatly reduces lot-to-lot variations.
- To ensure the reliability of circuit electrical performance in this environment, TI’s Space EP products have a temperature range of −55 to +125°C, with electrical parameters tested and guaranteed to operate over those conditions.
- The compounds used on Space EP products exceed the NASA-driven outgassing requirements in ASTM E-495 of total mass loss (TML) of less than 1.0% and a collected volatile condensable material (CVCM) of less than 0.1%.
- After packaging, every Space EP unit receives temperature cycling (20 cycles) or a similar reflow stress prior to electrical testing. This extended qualification is to ensure the device’s performance and reliability in the harsh environments of space going beyond the qualification of typical commercial and automotive components.
Space EP products can be recognized on TI’s website by the suffix "-SEP" on the product page and in the datasheet. The company’s easy-to-navigate parametric tables offer full visibility into all space plastic and ceramic ICs available and upcoming in multiple classifications.
Two Different Packages
To meet the needs of its space application customers, TI offers two different space-qualified packaging options:
Plastic: Offering smaller size, lower weight, and higher performance, it comes in two radiation levels. One is for radiation-hardened Qualified Manufacturers List (QML) Classes P and Y products optimized for medium-Earth-orbit (MEO, between 2,000 and 35,786 km above sea level) and geostationary-orbit (GEO) missions with high-quality and high radiation-tolerant requirements. The second type targets radiation-tolerant Space Enhanced Products (SEP) targeted for low-Earth-orbit (LEO, altitudes from 400 to 2000 km) missions with lower radiation and cost requirements.
Ceramic: The traditional go-to option, it meets a variety of government agency specifications in the United States. Manufacturers of ceramic-packaged space electronics have released ICs to the market under a qualification known as QML Class V.
In addition, TI’s QML Class P certified portfolio offers solutions across the entire spacecraft electrical power system (EPS), from solar panels to point-of-load power supplies.
Engineering the Next Frontier
TI’s inventory of space-grade products is immediately available. The company offers best-in-class products in both its QMLV/QMLP (typically identified by the -SP suffix) and radiation-tolerant (identified by the -SEP suffix) portfolios. Its SEP products are helping the LEO market grow as demand increases for small, affordable, and radiation-tolerant satellites.
TI is a pioneer in the spacecraft component business. Building on 60 years in the space market (Fig. 2), the company’s radiation-hardened products and systems expertise help meet mission-critical design requirements, including operating in space, for decades to come.
