The Vishay ILQ620 is a quad-channel transistor-output optocoupler in a 16-DIP through-hole package, offering 5300Vrms isolation between input and output. Each of the four channels provides a phototransistor output with a current transfer ratio (CTR) ranging from 50% to 600% at a forward current of 5mA. The input stage accepts both AC and DC drive, which simplifies coupling to bipolar signals such as line-voltage zero-cross detect or transformer-coupled gate drive. Output transistors are rated for up to 70V and 50mA per channel, with a typical Vce saturation of 400mV — enough to drive logic inputs or low-current relays directly.
Switching speed and timing — what 20µs rise time means for your design
Typical turn-on time is 3µs and turn-off time is 2.3µs, with a rise time of 20µs and fall time of 2µs. These are relatively slow by modern digital isolator standards, but perfectly adequate for 50/60 Hz line sensing, relay coil drive, PLC input modules, and status feedback loops where the signal bandwidth is under a few kilohertz. The 20µs rise time means the output transitions are not suited for high-speed serial interfaces or PWM above a few hundred hertz without significant pulse-width distortion.
Temperature range and environment
Rated for -55°C to 100°C operating temperature, the ILQ620 covers industrial and some military/aerospace environments. The wide temperature span suits outdoor telecom cabinets, motor drives in factory automation, and power supplies that see elevated ambient temperatures. The 5300Vrms isolation rating supports reinforced insulation requirements in mains-connected equipment.