CNY75 Optocoupler Technical Summary

Overview

The CNY75(G) Series is a high-performance optocoupler family consisting of a gallium arsenide infrared emitting diode optically coupled to a phototransistor. Designed for reliable signal isolation in demanding applications, this component provides electrical isolation between input and output circuits while transmitting analog or digital signals. The series meets stringent international safety standards for reinforced insulation applications.

Key advantages of the CNY75 include its high isolation voltage rating, stable current transfer ratio (CTR), and robust construction suitable for industrial environments. The special construction results in exceptionally low coupling capacitance, making it suitable for noise-sensitive applications.

Features

• High isolation voltage rating: 600V_RMS (848V peak)
• Rated impulse voltage (transient overvoltage) V_IOTM = 6kV peak
• Isolation test voltage (partial discharge test voltage) V_pd = 1.6kV
• Rated recurring peak voltage (repetitive) V_IORM = 600V_RMS
• Excellent creeping current resistance: CTI = 275 (Comparative Tracking Index)
• Minimum thickness through insulation ≥ 0.75mm
• Current Transfer Ratio (CTR) offered in 3 selectable groups
• Flame-retardant isolation materials (UL94-V0 rating)
• Extra low coupling capacitance (typical 0.3pF)
• Pollution degree 2 classification (per DIN/VDE 0110 and IEC 664)
• Climatic classification: 55/100/21 (IEC 68 part 1)
• Comprehensive safety approvals including:
  • BS 415
  • BS 7002
  • SETI: IEC 950
  • UL 1577 (File No: E 76222)

Applications

The CNY75 optocoupler series is designed for a wide range of isolation applications across multiple industries:

Industrial Automation

• PLC input/output isolation
• Motor control circuits
• Industrial communication interfaces
• Sensor isolation

Power Electronics

• Switch-mode power supply feedback circuits
• Inverter gate drive isolation
• Power factor correction circuits

Medical Equipment

• Patient-connected equipment isolation
• Medical monitoring systems

Telecommunications

• Line interface circuits
• Modem isolation

General Purpose

• Microprocessor system interfaces
• Ground loop elimination
• Noise suppression in signal transmission

Electrical Characteristics

The following table summarizes key electrical parameters (all values typical at 25°C unless otherwise specified):

Input Characteristics (IRED)

• Forward voltage (I_F = 60mA): 1.25V
• Reverse voltage: 5V
• Peak forward current (1μs pulse width, 300Hz): 1A
• Continuous forward current: 60mA
• Power dissipation: 100mW

Output Characteristics (Phototransistor)

• Collector-emitter voltage: 70V
• Emitter-collector voltage: 7V
• Collector current: 50mA
• Power dissipation: 150mW
• Dark current (V_CE = 10V): 100nA

Transfer Characteristics

• Current Transfer Ratio (CTR):
  • Group 1: 50-100% (I_F = 10mA, V_CE = 5V)
  • Group 2: 80-160%
  • Group 3: 130-260%
• Response time (I_F = 10mA, R_L = 100Ω):
  • Turn-on time (t_on): 3μs
  • Turn-off time (t_off): 4μs
• Isolation capacitance: 0.3pF (typical)

Isolation Characteristics

• Isolation voltage (V_IOWM): 600V_RMS
• Transient overvoltage (V_IOTM): 6kV peak
• Partial discharge test voltage (V_pd): 1.6kV
• Comparative Tracking Index (CTI): 275

Package Information

The CNY75 is available in a standard 6-pin DIP (Dual In-line Package) with the following mechanical characteristics:

• Package type: DIP-6 (dual in-line package)
• Mounting style: Through-hole
• Pin spacing: 2.54mm (standard DIP pitch)
• Row spacing: 7.62mm
• Package material: UL94-V0 flame retardant plastic
• Lead material: Tin-plated copper alloy
• Operating temperature range: -55°C to +100°C
• Storage temperature range: -55°C to +125°C
• Moisture sensitivity level (MSL): MSL 1 (unlimited floor life at <30°C/85% RH)

Pin Configuration

• Pin 1: Anode of IRED
• Pin 2: Cathode of IRED
• Pin 3: No connection
• Pin 4: Emitter of phototransistor
• Pin 5: Collector of phototransistor
• Pin 6: Base of phototransistor (typically left unconnected)

Recommended PCB Layout

For optimal performance and safety compliance:

• Maintain minimum creepage distance of 8mm between input and output circuits
• Provide adequate clearance (≥5mm) between primary and secondary side traces
• Use solder resist between input and output pins
• Avoid sharp edges on high voltage traces
• Consider using slot isolation in the PCB for reinforced insulation applications