The AQY212SZ is a miniature SOP4-pin PhotoMOS relay designed for low-level analog signal control in AC/DC dual-use applications. It features a 60V peak load voltage rating with a continuous load current of 500 mA, an extremely low off-state leakage current of maximum 1 µA, and a typical on-resistance of 0.83 O at 5 mA load current. The device operates over an ambient temperature range of -40°C to +85°C and provides fast switching performance with typical turn-on time of 0.65 ms and turn-off time of 0.08 ms. The AQY212SZ is widely used in telecommunications equipment, measuring and testing instruments, factory automation, security systems, and industrial robots where reliable low-signal switching and galvanic isolation are required.