Isolation barrier and CTR — the two numbers that decide fit
The VO617A-2X007T is a Vishay single-channel transistor-output optocoupler in a 4-SMD Gull Wing package. Its 5300 Vrms isolation voltage defines the reinforced insulation barrier between input and output — this is the spec that determines whether the part meets safety creepage requirements for mains-isolated circuits in industrial PSUs, motor drives, or PLC digital inputs. Current transfer ratio (CTR) is the gain of the optocoupler: with 5 mA forward current, the output transistor saturates at a collector current between 63% (3.15 mA min) and 125% (6.25 mA max). The 63% floor is the design-relevant number — it sets the minimum load current the opto can drive at a given LED current, which determines whether a 5 mA input can pull a 3.3 V logic input low or drive a relay coil directly.
Switching speed and output drive
Rise and fall times are 2 µs typical each; turn-on is 3 µs and turn-off 2.3 µs. This places the usable data rate around 100-200 kbps — fine for 50/60 Hz line synchronisation, PLC input sampling at 1 kHz, or slow serial isolation, but not for high-speed comms like CAN or RS-485. The output transistor is rated for 80 V collector-emitter and 50 mA continuous current. That 80 V ceiling covers 48 V industrial rails with 30 V margin; the 50 mA output can drive a small relay, a logic gate input, or a MOSFET gate through a series resistor without a buffer transistor.
Temperature range and forward drive
Operating from -55°C to 110°C, this optocoupler spans the full industrial and military temperature band. In an engine-bay ECU seeing 105°C ambient or a downhole tool at 85°C, the CTR derating with temperature must be factored — the 63% minimum is at 25°C; at 110°C the CTR typically drops to about 50-60% of the 25°C value, so the actual drive current at temperature may be lower. The absolute maximum forward current is 60 mA; for reliable long-life operation, design for 5-10 mA and keep below 20 mA to avoid LED degradation over temperature.
It is a current-production part suitable for new designs. ROHS3 compliant, no exemptions that would block EU or China RoHS markets.