A new line of leaded and SMD, single and multilayer varistors designed specifically for 12 V, 24 V and 42 V automotive applications is available from Stackpole Electronics Inc.
Product engineering manager Kory Schroeder said “Multilayer varistors fit the requirements for automotive circuit protection because they are volumetrically efficient and fast reacting, yet still able to withstand large amounts of current and energy.”
The chip-style, surface-mount multilayer AV series is available in 0805 to 3225 case sizes with single pulse peak current from 120 A to 2000 A (8/20 µsec waveform) and single pulse transient energy spikes from 0.3 Joules to 17 Joules (10/1000 µsec waveform).
The through-hole-style AV series employs round and square-shaped designs to achieve superior transient energy absorption due to improved internal energy distribution. Devices are available in single layer (for >50 J) and multilayer (<50 J) components, in disc sizes from 6 mm to 40 mm. The AV series offers single pulse peak current from 400 A to 2000 A (8/20 µsec waveform) and single pulse transient energy spikes from 1.6 Joules to 76 Joules (10/1000 µsec waveform). In comparison with typical round automotive disc varistors, the AV series offers better electrical characteristics in a much smaller size, according to Schroeder.
“With high maximum current capabilities, superior ratings for the automotive V jump test and load dump energy requirements--the SMD and through-hole styles of the AV series provide excellent bidirectional transient voltage protection for sensitive automotive electronics,” he said. Applications include antilock braking systems, direct ignition, airbag controls and windshield wiper motors in order to combat destructive voltage transients.