High voltage transients are generated by inductive loads (e.g. motor windings or long wire harnesses). In order to provide sufficient protection in an automotive environment, e.g. the load dump voltage, Infineon uses transistor structures withstanding a continuous supply voltage
V I up to 45V. Additionally, several ICs offer protection against load dump pulses up to 65V (e.g. TLE4270, TLE4271-2).
For details please refer to the “Absolute Maximum Ratings” table in the datasheet.
Exceeding any of these values may damage the IC independent of pulse length. Therefore, a suppressor diode is suggested to provide protection from overvoltage. Moreover, transients can be buffered with an input capacitor that takes the entire energy or some of it, attenuating the surge at the IC input pin I.
In order to protect the voltage regulator output against short circuits to the battery, the maximum voltage allowed at the output Q is much higher than the nominal output voltage. Therefore, all trackers and some voltage regulators tolerate an output voltage up to V Q = 45V, which protects them against shorts to battery at the output.
Load dump transient