Vishay VOS618A-3T Optocoupler for High-Efficiency Signal Isolation

• High CTR at Low Input Current: The -3 bin (100 %–200 %) enables efficient signal coupling even with minimal LED drive, beneficial for low-power designs.
• High Isolation Voltage: With a 3750 VRMS isolation test rating and repetitive peak isolation well over 500 V, it safeguards high-voltage to low-voltage interfaces.
• Compact Low-Profile Package: SSOP-4 half-pitch package allows slim board real estate usage, making this optocoupler suitable for space-constrained applications.

The Vishay VOS618A-3T is a member of the VOS618A series of optocouplers, featuring a GaAs infrared-emitting diode emitter optically coupled to a silicon planar phototransistor detector, all housed within a miniature 4-pin SSOP-4, half-pitch (50 mil lead-pitch) package.
This version, marked “-3T”, corresponds to the CTR (current transfer ratio) bin of 100 % to 200 % (IF = 1 mA, VCE = 5 V) for the VOS618A-3 variant. 
The product is designed for transferring signals between two electrically isolated circuits, offering high isolation voltage, low coupling capacitance, and robust performance in demanding environments such as telecom, industrial and battery-powered equipment.

Features

• High current transfer ratio (CTR) even at low input current.

• Low-profile SSOP-4 package with half-pitch, 50 mil lead spacing making it suitable for compact board designs.

• High collector-emitter voltage rating: VCE(o ) = 80 V.

• High isolation test voltage: 3750 VRMS between emitter and detector (1 minute).

• Low coupling capacitance (e.g., 0.3 pF typical) enabling high common-mode transient immunity.

• Material categorization for RoHS/REACH compliance.

Specifications

• Absolute Maximum Ratings (Tamb = 25 °C unless specified):

  • Input reverse voltage, VR: 6 V.

  • Input forward current, IF: 50 mA.

  • Output collector-emitter voltage, VCEO: 80 V.

  • Output emitter-collector voltage, VECO: 7 V

  • Isolation test voltage VISO: 3750 VRMS (1 minute) between emitter and detector.

  • Storage temperature range, Tstg: –55 °C to +150 °C.

  • Ambient operating temperature range, Tamb: –55 °C to +110 °C.

• Electrical Characteristics (Tamb = 25 °C unless otherwise specified):

  • Forward voltage VF (IF = 50 mA): min 1.1 V, typ 1.5 V.

  • Reverse current IR (VR = 6 V): max 10 µA.

  • Input capacitance CI (VF = 0 V, f = 1 MHz): 8 pF.

  • Collector-emitter leakage current ICEO (VCE = 10 V): max 100 nA.

  • Collector-emitter breakdown voltage BVCEO (IC = 100 µA): min 80 V.

  • Coupling capacitance CC (f = 1 MHz): typ 0.3 pF.

  • Collector-emitter saturation voltage VCE(sat) (IF = 1 mA, IC = 0.25 mA): max 0.4 V.

  • Cut-off frequency fCTR (IF = 10 mA, VCC = 5 V, RL = 100 Ω): typ 119 kHz.

  • Current Transfer Ratio CTR (IF = 1 mA, VCE = 5 V): for “-3” bin: min 100 %, max 200 %.

• Safety & Insulation Ratings:

  • Climatic classification: 55/110/21.

  • Maximum rated withstanding isolation voltage VISO (40 %–80 % RH, AC test, 1 min): 3750 VRMS.

  • Maximum repetitive peak isolation voltage VIORM: 565 Vpeak.

  • Isolation resistance RIO (Tamb = 25 °C, VDC = 500 V): ≥ 10¹² Ω.

Applications

• Telecom equipment: performing signal isolation between high-voltage and low-voltage circuits.

• Industrial controls: for example, PLCs, motor drives, and programmable logic controllers requiring galvanic isolation.

• Battery-powered equipment: where low input current and compact packaging are critical.

• Office machines: printers, scanners and other equipment where signal integrity and isolation are required.

• Programmable controllers or sensory interface modules where compact form factor and high isolation are required.