Varistors for automotive and industrial circuitry

April 22, 2013 // By Christoph Hammerschmidt
Passive component manufacturer AVX has added several new varistors to its TransGuard and TransGuard Automotive Series. Based on AVX’s zinc-oxide varistor technology, the extended TransGuard series provide a broader range of voltage and energy rating options than previously available.

Both AVX's TransGuard and TransGuard Automotive series varistors feature a high-energy monolithic multilayer construction that provides circuit protection from voltage transients caused by ESD, lightning, inductive switching, automotive related transients, and other disruptions. The two TransGuard series also feature non-linear, bi-directional voltage-current characteristics similar to those of back-to-back Zener diodes, but with the added advantage of greater current and energy-handling capabilities, as well as EMI/RFI attenuation. Lead-free and RoHS compliant, both series are designed for use in temperatures ranging from -55°C to +125°C.

The varistors handle a peak current up to 2000A, transient energy up to 12J, and low leakage currents under standard DC operating conditions. Both series are also available with Ni/Sn-plated terminations for lead free soldering or with Pd/Ag terminations for hybrid assembly.

TransGuard Automotive Series varistors are available in 0402 to 2220 surface-mount case sizes, as well as with radial leads. Featuring a working voltage range of 5.6-85 VDC, the AEC-Q200-qualified series exhibits high current and high energy handling capabilities, multi-strike capability, and faster than 1 nsec response to ESD strikes, which makes it well-suited for protecting against automotive transients in wide range of applications, including: safety applications (airbags, ABS, etc.), body electronics (ECU, sensors, etc.), drive train (water pump, power steering), comfort and convenience (electric mirror, audio), and hybrid and electric vehicles (engine start/stop, electric drive).

TransGuard series varistors are available in 0201 to 2220 surface-mount case sizes, as well as with radial and axial leads. Exhibiting a working voltage range of 3.3–85 VDC, the series is suitable for a wide range of professional, industrial, and commercial applications.