The AQY212EH is a DIP4-pin PhotoMOS relay featuring reinforced insulation rated at 5,000 Vrms with more than 0.4 mm internal insulation distance between inputs and outputs, conforming to EN41003 and EN60950 standards. This device is designed to control low-level analog signals with extremely low closed-circuit offset voltage, enabling distortion-free signal transmission. It offers high sensitivity with a maximum continuous load current of 0.55 A at 60 V peak AC load voltage, combined with low on-resistance of 0.25 O typical and 0.5 O maximum. The relay exhibits low off-state leakage current of maximum 1 µA and operates reliably across an ambient temperature range of -40°C to +85°C. Typical applications include modem and telephone equipment, industrial plant control, security systems, and sensing equipment where galvanic isolation and low-signal switching are required.