The AQY211EH 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, and offers high sensitivity with a maximum load current of 1 A at 30 V peak AC and a typical on-resistance of 0.25 O. The relay operates with a 5 mA input current, features a 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 modems, telephone equipment, industrial plant equipment, security systems, and sensing equipment where galvanic isolation and low-level signal switching are required.