3750Vrms isolation in a 6-SOIC — what this photocoupler is for
The Toshiba TLP2301(E is a single-channel DC-input transistor-output photocoupler in a 6-SOIC package with 4 leads. The wide current transfer ratio (CTR) range — 50% minimum to 600% maximum at 1mA forward current — gives you flexibility to trade off LED drive current against output load resistance, which matters when you're sizing the input-side resistor or trying to keep the LED power budget tight.
With a minimum CTR of 50% at 1mA If, you can guarantee the output transistor will saturate with a reasonable load resistor even at low LED current. The 600% maximum means the part can also work at very low LED drive (sub-mA) if you need to save power on the input side — useful in battery-powered or loop-powered isolators. The 300mV Vce(sat) maximum keeps the output drop low when the transistor is fully on, so you don't lose much headroom in the logic-level signal path.
The 40V output breakdown and 50mA per-channel output current are enough to drive a logic gate input, a relay coil with an external transistor, or a small DC load directly.
Package and mounting — 6-SOIC with 4 leads
Housed in a 6-SOIC body (0.173" wide, 4.40mm width) with only 4 leads populated, the TLP2301(E saves board area compared to a DIP-8 photocoupler. It's a surface-mount device, so it reflows with the rest of your SMD passives and ICs. Ships in Tube — not Tape & Reel — so plan your pick-and-place feeder setup accordingly if you're running high-volume assembly.