Isolation and CTR — the two numbers that define the BOM fit
The TLP293(YH-TPL,E is a single-channel transistor-output optoisolator from Toshiba. Its 3750Vrms isolation rating is the figure that decides whether this part can sit on a mains-referenced secondary side — enough margin for reinforced insulation in 240 VAC equipment, though not for 600 V industrial bus isolation. The current transfer ratio (CTR) spans 75% to 150% at 500 µA forward current. That range tells you the gain margin for logic-level translation: at 5 V supply with a 10 kΩ pull-up, the output swings rail-to-rail across the full CTR window. A part with CTR below 50% would need a lower-value resistor, increasing idle power.
Speed and drive — switching times and output capability
Rise and fall times are 2 µs and 3 µs typical; turn-on and turn-off times are both 3 µs typical. That puts the usable switching frequency around 50–100 kHz for isolated gate-drive or signal-isolation applications — fast enough for most industrial I/O, too slow for high-speed comms isolation. Output transistor is rated for 80 V collector-emitter and 50 mA continuous current per channel. The 300 mV max Vce(sat) at rated current keeps conduction loss low in saturated switching — a factor when driving a relay coil or a low-side load directly.
Temperature range and package — where it fits on the board
Lifecycle status is Active, meaning Toshiba is still producing this suffix. RoHS compliant — no lead exemption to track.
The single-channel variant is the most common in the TLP293 family; the four-channel TLP293-4(LA-TR,E is a separate order code with the same isolation and CTR specs but different pinout.