Voltage and current transient protection for analog integrated circuits using memristor models and circuit simulations

In modern circuit design perspective, protection of high-speed analog circuit design, against electromagnetic transients is critically important for ensuring long-term reliability and robustness of systems and equipment that incorporate integrated circuits. Electromagnetic transients can introduce erroneous voltage and current levels that may exceed the tolerance limits of circuit components. This thesis investigates the use of memristor devices as circuit protection elements against transient voltage spikes. To facilitate state transitions between the memristor's resistance levels, a bias-tee network is proposed for both applying the necessary bias voltage and isolating the DC component from the signal path. The design of these bias-tee circuits was conducted using impedance matching techniques and the maximum power transfer theorem, to ensure signal integrity without the loss of signal quality. Simulations were implemented in the LTspice environment, and their results were analyzed and compared with MATLAB. In LTspice, test signals representing analog audio and analog video interfaces were modeled, along with transient voltage disturbances and memristor circuit behavior. To design the simulation circuits, interface characteristics and technical requirements were examined. In the proposed design, traditional components such as TVS (Transient Voltage Suppression) diodes and AC coupling capacitors were retained, and a memristor model - based on the Yakopcic research group's model - was connected in series to the interface. This hybrid design configuration enabled the development of a novel protection circuit topology. According to the simulation results, the memristor-based structure functioned in coordination with the TVS diode and exhibited a faster response compared to the conventional solution. The additional protective elements prevented transient voltage fluctuations caused by electromagnetic disturbances from reaching the interface during the exposure period, thus helping to mitigate potential damage to analog input and output nodes. This thesis proposes a new circuit topology for transient voltage protection in high-speed analog interfaces, enabling savings in both board space and component count. Implementing a comparable level of protection without using a memristor would require additional circuit elements and more complex electrical circuit design. Although simulation-based protection designs were proposed for two different interface types, further research is necessary to evaluate their performance and feasibility with other types of interfaces in physical implementations. Based on the voltage applied across their terminals, memristors can change their resistance states. This study investigates whether this property can be effectively leveraged in the design of a protection circuit capable of suppressing transient waveforms. For initial protection, TVS diodes are employed to clamp the voltage surges. Additionally, a dedicated biasing circuitry is proposed to control the resistance state transitions of the memristor passively and actively within the protection scheme.