Bench Talk

Join journalist Tommy Cummings for a weekly look at all things interesting, new, and noteworthy for design engineers.

It stands to reason: The more gadgets in the market, the higher demand for tantalum capacitors.

Tantalum capacitors have numerous applications because of their long-term stability, high capacity, reliability, and low leakage currents. As a class of electrolytic capacitors, tantalum capacitors are passive components widely used in communications, aerospace, and military industries, submarine cables, advanced electronic devices, civil appliances, televisions, and much more.

That's a lot of work for a small product. Many tantalum capacitors are no larger than a grain of rice. Tantalum capacitors are made of metal tantalum (Ta) as the anode material. The manufacturing process is multi-layered—literally. The anode starts as a pellet of porous tantalum metal covered by an insulating oxide layer that forms the dielectric, surrounded by liquid or solid electrolyte as a cathode. The capacitors can also include silver, carbon, or polymer. The resulting small form capacitors mean less real estate used on printed circuit boards, which allows for greater packing densities—good news for design engineers.

In this week's New Tech Tuesdays, we'll check out tantalum capacitors from Panasonic, KEMET Electronics, and Vishay/Sprague.

Panasonic POSCAPTM TQC Conductive Polymer Tantalum Solid Capacitors are best suited as bypass capacitors on a 12V motor driver or for the input side of a DC-DC converter. They're ideal for high-voltage, low equivalent series resistance (ESR), and low-profile applications. The capacitors can endure up to +105°C operating temperature while providing up to 2,000 hours of endurance, making them effective in small-space applications such as notebooks, tablets, and small desktop devices. They're available in a wide range of case sizes and voltage ranges.

KEMET Electronics TF08 Ultrathin Facedown Polymer Tantalum Capacitors are most effective in densely populated circuits where space restrictions do not allow for larger and more commonly available case sizes. TF08 capacitors' typical applications include DC/DC converters, audio/sound circuits (mobile phone and base stations, smartphones, MP3 players), power-supply inputs, portable electronics (notebook PCs, displays, SSDs, HDDs and USBs, digital cameras, GPS navigation, Wi-Fi^® modules), telecommunications, consumer electronics (analytical and test equipment, high-speed servers), high-voltage applications such as 12V to 48V power input rails. The TF08 is a solid electrolytic capacitor with a conductive polymer cathode capable of delivering low ESR and improved capacitance retention at high frequencies.

Vishay/Sprague T18 Ultra-High Capacitance Wet Tantalum Capacitors are optimized for timing, filtering, energy hold-up, and pulse power applications in power supplies for space and avionics applications. The wet tantalum T18 series features a 22µF to 1200µF capacitance range and a tantalum-case with Glass-to-Tantalum Hermetic Seal for -55 °C to +125 °C plus an increased thermal shock capability of 300 cycles.

Tantalum capacitors are muscle capacitors. They offer enhanced performance and high reliability with low ESR, stable capacitance across temperature and voltage change, and no aging effects. Despite their size, tantalum capacitors offer volumetric efficiency in high-density applications. They are available in many capacitance and voltage ranges to suit most commercial, industrial, military, and consumer applications.