Overload protection circuit for motor vehicle electronic systems - has zener diode and capacitor in parallel with integrated circuit and following series resistor

摘要

The overload protection circuit is esp. for fuel injection systems having integrated electronic circuits. The circuit contains a Zener diode (D) and a capacitor (C) in parallel with the input terminals (EK) of the integrated circuit (S) to be protected and following a series resistor (RV). The Zener diode breakdown voltage is above the normal voltage fluctuations at the fuel injection system, but below breakdown voltages for the integrated circuit. The resistor (RV) limits the current flowing through the diode during the appearance of excess voltage pulses. The resistor also forms with the capacitor a low pass filter for interference pulses lying below the diode voltage.