Specifications: The APY221EH is a miniature SMD-4 PhotoMOS solid-state relay with a 1 Form A (SPST-NO) contact. It is rated for 200mA and 60V AC/DC. Key specifications include a 2Ω on-state resistance, 5000Vrms isolation voltage, and fast, symmetrical 50μs switching times. It operates from -40°C to 85°C and is controlled by 1.2-1.4VDC. Application Scenarios: Designed for high-density PCB designs requiring reliable, isolated switching of low-power signals. Applications include communication equipment (routers, switches) for port control, medical monitoring device signal isolation, industrial sensor interfaces, battery-powered portable instruments, and as a building block in modular I/O systems for factory automation.