The AQY280EHA is a single-channel PhotoMOS relay designed for general-purpose AC/DC switching applications with reinforced insulation. It features a 400V peak load voltage rating with a maximum continuous load current of 120 mA, delivering stable switching performance without metallic contact parts. The relay incorporates a high-sensitivity LED input requiring only 5 mA to operate, combined with a low on-resistance of 20O at maximum load current and an extremely low off-state leakage current of 1 µA. With reinforced 5,000V AC isolation between input and output (exceeding 0.4 mm internal insulation distance per EN41003 and EN60950), the AQY280EHA is well-suited for modem, telephone equipment, security systems, and sensor applications requiring reliable galvanic isolation and compact DIP4 packaging.