Automotive varistors cut response time to ESD strikes by half

August 16, 2013 // By Graham Prophet
AVX TransFeed multilayer ceramic TVS devices provide state-of-the-art overvoltage protection and EMI attenuation over a broad range of frequencies in automotive applications.

AVX's TransFeed Automotive Series combines the best electrical characteristics of its TransGuard Transient Voltage Suppressors (TVS) and its Feedthru Capacitors in a single chip to provide state-of-the-art overvoltage circuit protection and EMI reduction over, the company says, a much broader range of frequencies than comparable devices. Featuring a unique multilayer ceramic construction in a feedthrough configuration, the TransFeed Automotive Series responds to transient events faster than any other TVS device and provides significant EMI attenuation when in the off state. Qualified to AEC-Q200, the series is suitable for automotive applications, including: drive by wire, dimming mirror circuits, filtering/protection on microcontroller I/O lines, filtering/protection on interface I/O lines, power line conditioning, power regulation, and LCD dashboard drivers, among others.

The reduction in parallel inductance typical of the feedthru chip construction (vs. the construction of standard TVS or ceramic capacitor chips) provides the TransFeed Automotive Series with two significant advantages, the first of which is faster turn-on time. Measured response times for TransFeed devices range from 200-250 psec, which is less than half that of the fastest bipolar TVS solutions available. The second electrical advantage of lower parallel inductance coupled with optimal series inductance is enhanced attenuation characteristics. TransFeed Automotive Series varistors exhibit excellent attenuation at high self-resonant frequency with a much flatter roll-off characteristic than comparable devices, resulting in EMI filtering over a much broader frequency spectrum.

Working voltage range is 5.6-18 VDC, clamping voltage range is 18-50V, energy rating is 0.05-0.3J, peak current is 15-120A, and maximum feedthrough current is 0.2-1A. Rated for use in temperatures ranging from -55ºC to +125ºC, the series is available in 0805 and 0612 cases with Ni Barrier/100% Sn terminations.

“The new Automotive TransFeed Series varistors provide outstanding bi-directional ESD protection coupled with low parallel induction, excellent decoupling capabilities for high di/dt environments, and significant noise reduction in digital circuits,” said Jiri Machanicek, Product Manager at AVX.

Lead time for the series is 14 weeks.