The AQY212FG2S is a space-saving SOP4-pin high-capacity PhotoMOS relay with built-in input resistor, designed for voltage-sensitive switching applications. This miniature relay features a continuous load current rating of 1.25A at 60V, with a peak load current capability of 3A (100ms, 1-shot), and operates with a recommended input voltage of 5V. The integrated input resistor eliminates the need for external mounting components, reducing assembly time and simplifying PCB design while maintaining a compact footprint. Key electrical characteristics include an on-resistance of 0.2O (typical at maximum load) and turn-on/turn-off times of 0.7ms/0.1ms respectively, with I/O isolation voltage of 500Vrms. The device operates reliably across an ambient temperature range of -40°C to +85°C and is commonly used in measuring and testing equipment, semiconductor testing, probe cards, dataloggers, board testers, and telecommunications applications.