The TCLT1004: The 5000Vrms isolation rating qualifies this optocoupler for reinforced insulation in mains-referenced circuits — think motor-drive IGBT gate drives, SMPS feedback loops, or PLC digital inputs where the primary side sees rectified 230VAC and the secondary must stay galvanically separated for operator safety. Current transfer ratio spans 160% minimum to 320% maximum at If=10mA. A 160% floor means the output transistor can sink at least 16mA with 10mA LED drive — enough margin to saturate a 5V logic input without starving the LED side. The 320% ceiling tells you the part is not a high-gain part; it is a standard-gate optocoupler, not a Darlington output, so switching speed stays predictable.
Switching speed and temperature range
Rise and fall times are 3µs and 4.7µs typical; turn-on and turn-off times are 6µs and 5µs typical. This puts the usable data rate around 50-100 kbps — fine for 50/60Hz zero-crossing detection, relay coil feedback, or slow digital isolators, but not for high-speed comms like I²C or CAN. The -55°C to +100°C operating range covers industrial enclosures and under-hood automotive environments without derating.
Package and sourcing posture
Housed in a 4-SMD gull-wing package with a 4-SOP supplier device package designation. The gull-wing leads are 1.27mm pitch standard — no fine-pitch reflow challenges. Surface-mount assembly with tape-and-reel or cut-tape options for prototype or production volumes.