Dual Darlington optocoupler with 5.3 kV isolation
The Vishay ILD55 is a dual-channel Darlington-output optocoupler in an 8-DIP through-hole package. It provides 5300 Vrms galvanic isolation between the DC input LED and the Darlington output stage, making it suitable for isolating logic signals in industrial control, PLC I/O, and motor-drive feedback paths. Each channel delivers up to 125 mA output current with a maximum Vce saturation of 1 V, and the output can handle up to 55 V. The minimum current transfer ratio of 100% at 10 mA forward current ensures reliable switching even with moderate LED drive.
Switching speed and temperature range
Typical rise and fall times are 10 µs and 35 µs respectively — this suits low-to-moderate speed isolation applications such as status feedback, relay replacement, or 50/60 Hz zero-cross detection. For higher data rates, a phototransistor-output optocoupler would be a better fit. The operating temperature range of -55°C to +100°C covers industrial and outdoor environments, including cold-start conditions and enclosures near warm machinery.