Isolation rating and where it fits on the board
The 4170Vrms isolation voltage is the headline spec — it's what qualifies this part for galvanic isolation between a low-voltage control side and a higher-voltage load side, like a PLC digital output driving a 24V relay or a motor contactor coil. That rating is a full 1.7kVrms above the 2500Vrms parts in the same package, so if your BOM calls for 4N26SR2M, it's because the creepage or test voltage requirement pushed you past the baseline opto. The DC input type means the LED is driven with a steady current — no AC line rectification on the primary side. The transistor output with base gives you access to the base node for external bias or speed-up networks, which matters if you're pushing the 2µs turn-on/turn-off times and need to tailor the switching threshold.
Temperature range and production status
The surface-mount 6-SMD gull-wing package is the reeled version of the standard 4N26 DIP, so pick-and-place lines handle it directly.
Sourcing and quoting for volume
For volume pricing and lead time, submit an RFQ with your target quantity and preferred delivery window. The part is active across multiple distribution channels, so competitive quotes are available — no single-source bottleneck to navigate.