Isolation and signal transfer for industrial control boards
The TCET1100G: This isolation rating is the primary spec for breaking ground loops and protecting low-voltage logic from high-side transients in motor drives, PLC I/O modules, and industrial power supplies.
Current transfer ratio and switching speed — what they mean for the driven circuit
The CTR spans 50% minimum to 600% maximum at If=5 mA, giving a wide gain window. A 50% floor means the output transistor sinks at least 2.5 mA with 5 mA input — enough to drive a standard logic gate or a 5 V relay coil through a base resistor. The 600% ceiling means the same input can saturate the output into a higher-impedance load without overdriving the LED side. Rise and fall times are 3 µs and 4.7 µs typical; turn-on and turn-off times are 6 µs and 5 µs typical. This places the TCET1100G in the medium-speed class — suitable for 50/60 Hz line synchronisation, status feedback at PLC scan rates, and DC bus voltage sensing where the signal changes in the millisecond range. For faster PWM or serial data, a logic-output optocoupler would be needed. The output transistor is rated for 70 V collector-emitter and 50 mA continuous current.
Operating temperature from -40°C to 100°C covers industrial enclosures, outdoor telecom cabinets, and under-hood automotive auxiliary circuits. Tube packaging keeps the leads aligned for auto-insertion. Forward voltage is 1.25 V typical at If=20 mA; the LED can handle up to 60 mA continuous.