A Fail-Safe High-Pass Filter Circuits with Diode Recovery Time

A high-pass filter is a circuit that uses the properties of a resistor and capacitor to filter specified high frequencies from the input side to the output side. In the event of a capacitor failure, increasing or decreasing the value of the capacitor causes the output frequency to change. That can cause consequences in the next part of the circuit. This paper presents an inherent fail-safe high pass filter circuit with diode recovery time. The recovery time property of a rectifier diode is not conduct current with reverse bias, which returns to conduct current when the input frequency is higher than the specified value of the diode. Design a circuit using two diodes connected in reverse in series instead of a capacitor. Diodes are semiconductor devices, they do not increase or decrease the value issues like capacitors, that is inherently fail-safe. Test circuit with 1N4007 diode at frequencies of 1 kHz to 50 kHz. The simulation results with the LTspice program and failure analysis with failure mode and effects analysis (FMEA) method.