Specifications: The APY201S is a low-power PhotoMOS SSR in a standard SOP-4 package. It is a 1 Form A (SPST-NO) relay rated for 100mA at 60V AC/DC. It has a 3Ω on-state resistance, provides 2500Vrms isolation, and switches with 150μs (on) and 50μs (off) times. It operates from -40°C to 85℃ with a 1.2-1.5VDC input. Application Scenarios: A cost-effective, general-purpose relay for low-power signal or load switching. Ideal for isolated digital I/O, indicator/LED driving, sensor interface isolation, low-power relay coil driving, and as a microcontroller interface in consumer electronics, appliances, and industrial controls, providing reliable isolation and switching in the most common package style.