What the 35-ohm on-resistance means for your signal chain
The AQY214SX is a PhotoMOS™ AQY series solid-state relay from Panasonic, switching AC or DC loads up to 100 mA across a 0 V to 400 V range. The 35-ohm on-state resistance is the key trade-off: it limits the voltage drop across the relay at full load to 3.5 V, which is acceptable for many instrumentation and telecom signal paths but too high for precision analog switching where a sub-ohm reed relay would be needed.
The surface-mount termination and Tape & Reel packaging suit automated pick-and-place assembly. Keep the trace width adequate for 100 mA continuous.
Listed as Active by Panasonic Electric Works. The base product number AQY214 covers the family; the SX suffix indicates the Tape & Reel packaging variant.