Fabrication and Experimental Analysis of a Multi-Voltage Level Switching Circuit

This paper presents the fabrication and experimental characterization of a multi-voltage level switching circuit with 6 channels designed to interface low-voltage control signals with a high-voltage domain. The circuit enables the switching of a 25 V load, such as a relay or a DC motor, using control signals ranging from 1.8 V to 5 V. This makes it compatible with multiple signaling protocols, including LVCMOS (Low voltage complementary metal oxide semiconductor) and TTL (transistor-transistor logic). The in-house fabricated circuit integrates optocouplers, PNP transistors, and resistive voltage dividers, ensuring electrical isolation, precise control, and reliable operation. The experimental characterization examines key performance metrics, including the switching time, rising time, and fall time of the output signals, under various signaling protocols such as LVCMOS18, LVCMOS33, and TTL.