Automotive circuit protection; high temperature, low leakage varistors

January 28, 2015 // By Graham Prophet
Qualified to AEC-Q200, AVX’ high temperature, low leakage CANATL series automotive controlled area network varistors exhibit extremely low leakage (≤1 µA at 32 VDC, 25°C) and are tested, qualified, and specified at 150°C, suiting them for use in high temperature engine-compartment automotive applications, such as transmission control units (TCUs), brake control modules (BCMs), data lines, bus interface units, and other capacitance sensitive applications.

Based on AVX’s multilayer varistor (MLV) technology, which combines circuit protection and EMI/RFI attenuation functions in a single, high reliability device, CANATL series automotive varistors are zinc oxide based ceramic semiconductor devices that exhibit non-linear, bi-directional voltage current characteristics similar to back-to-back Zener diodes with an EMC capacitor in parallel. In addition to the space savings provided by enabling EMI/RFI attenuation in the off-state, CANATL series multilayer varistors provide several valuable performance advantages over diodes, including: high in-rush current capacity (8A for 20 µec), a high 25 kV (HBM Level 6) ESD rating, low capacitance (10 pF) to minimise signal distortion, no derating over operating temperatures, and very fast response times, which clamp the energy before it reaches its maximum. CANATL series varistors also exhibit multi-strike capability, good solderability, and an FIT rate of ≤0.1 per billion hours.

Rated for use in temperatures spanning -55°C to 150°C, CANATL series automotive varistors are currently available in a 0603 case rated for 32 VDC operating voltage.