2020 Littelfuse, Inc.
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Electrical Threats
THREAT: ELECTROSTATIC DISCHARGE (ESD)
ESD is characterized by fast rise times and high peak voltages and currents up to 30A, which can melt silicon and conductor traces. Even when ESDs don't cause catastrophic failures, electrical currents due to ESD can change the state of internal logic, causing a system to latch up and behave unpredictably or cause corruption of a data stream. Without adequate protection, ESD can damage control units, infotainment electronics, sensors, fuel injectors, valves, motors, powertrains, and dozens of other components. Sometimes, a component or circuit is damaged by ESD, creating latent defects that later progress to premature failures.
TVS Diode Arrays
Because of their high-speed response to overvoltages, TVS Diode Arrays are widely used for ESD protection in automotive electronics. Automotive-qualified SPA TVS Diode Arrays from Littelfuse are available in a range of compact surface-mount packages to fit into any layout.
Electrical Threats and New Automotive Technologies
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THREAT: SWITCHING LOADS IN POWER ELECTRONICS CIRCUITS
In modern automotive designs, all on-board electronics are connected to the battery and the alternator. However, the output of the alternator is unstable and requires further conditioning before it can be used to power the vehicle's other systems. During the powering or switching of inductive loads, the power is temporarily interrupted, and unwanted voltage spikes or transients are generated. If left unchecked, these transients would be transmitted along the power line and into the electronic modules.
Varistors
Automotive-qualified Metal Oxide Varistors (MOVs) and Multilayer Varistors (MLVs) protect against voltage transients induced by load dump and other transient events. When exposed to high-voltage transients, the varistor impedance changes by many orders of magnitude-from a near open- circuit to a highly conductive level-clamping the transient voltage to a safe level. Choose from radial-leaded MOVs in disc sizes from 5mm to 20mm. Also, surface-mounted MLVs are available.
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