RF signal path relay — what the 250 mA and 1.25 Ohm mean for your board
The AQY221FR2VW is a PhotoMOS™ relay from the AQY series, configured as a SPST-NO (1 Form A) switch for AC or DC RF signals. Its 250 mA continuous load current and 1.25 Ohm max on-state resistance define the insertion loss and signal integrity ceiling in the RF path — the 1.25 Ohm series resistance adds about 0.1 dB loss into a 50-Ohm system, which is acceptable for many RF switching applications up to several hundred MHz.
NRND — plan your BOM migration now
That means it is still available for existing production but should not be designed into new boards. For existing BOMs, the part remains orderable through independent distribution channels — availability and pricing are confirmed at RFQ time. New designs should evaluate functionally equivalent PhotoMOS relays in the same AQY family with comparable package and ratings.
Package and board-fit — 4-SSOP with SMD tabs
The load voltage range of 0 V to 40 V covers common signal-level rails (5 V, 12 V, 24 V) and low-voltage analog paths. The SPST-NO topology is a normally-open switch — the relay closes when the input LED is forward-biased at 1.3 VDC.