CNY18

CNY18 Optocoupler Technical Summary

Overview

The CNY18 is a high-reliability optocoupler device consisting of an infrared gallium arsenide (GaAs) emitting diode optically coupled to a phototransistor. Housed in a hermetically sealed TO72 metal can package, this component is designed for applications requiring electrical isolation, noise immunity, and stable performance across varying environmental conditions. The CNY18 is particularly suited for industrial, medical, and telecommunications systems where DC isolation and signal integrity are critical.

Key Features

• Hermetically Sealed Package: TO72 metal can construction ensures protection against moisture and contaminants
• High Isolation Voltage: 500V DC isolation test voltage between input and output
• Low Coupling Capacity: Minimizes capacitive interference in sensitive circuits
• Group-Selected CTR: Current Transfer Ratio (CTR) is pre-sorted into selection groups for design consistency
• Temperature-Stable Performance: Low temperature coefficient of CTR maintains stable operation across temperature ranges
• Reliable Construction: Manufactured by Telefunken Semiconductors to military-grade standards

Applications

• Industrial control system isolation
• Medical equipment patient isolation barriers
• Telecommunications line interface circuits
• Power supply feedback loops
• Microprocessor system interfaces
• Ground loop elimination in analog systems
• Noise suppression in digital communication lines

Electrical Characteristics

Absolute Maximum Ratings

• Reverse Voltage (V_R): 3V
• Forward Current (I_F): 60mA
• Power Dissipation: 100mW
• Operating Temperature Range: -55°C to +100°C
• Storage Temperature Range: -55°C to +125°C

Optical Characteristics

• Emitter Wavelength: 940nm typical
• Rise Time (t_r): 3μs maximum
• Fall Time (t_f): 4μs maximum
• Isolation Capacitance: 0.5pF typical

Current Transfer Ratio (CTR)

The CTR is guaranteed in selection groups as follows:

• Group A: 20-40%
• Group B: 40-60%
• Group C: 60-80%
• Group D: 80-120%

Package Information

TO72 Metal Can Package

• Package Type: 4-lead hermetically sealed metal can
• Dimensions: 5.2mm diameter x 4.7mm height
• Lead Material: Kovar with gold plating
• Window Type: Clear optical lens
• Weight: 0.35g typical

Pin Configuration

• Pin 1: Anode (A) - Infrared emitter diode anode
• Pin 2: Cathode (C) - Infrared emitter diode cathode
• Pin 3: Collector (C) - Phototransistor collector
• Pin 4: Emitter (E) - Phototransistor emitter

Reliability Data

• MTBF: >1,000,000 hours at 25°C
• Isolation Resistance: >10¹¹Ω at 500V DC
• Moisture Resistance: MIL-STD-202 Method 106 compliant
• Vibration Resistance: 10-2000Hz, 20G per MIL-STD-883

Design Considerations

When implementing the CNY18 in circuit designs, consider the following:

• Always operate within specified current limits to prevent LED degradation
• For best CTR linearity, maintain I_F between 1-10mA
• Use appropriate current-limiting resistors for the emitter diode
• Keep traces short for high-speed switching applications
• For high-voltage applications, maintain proper creepage and clearance distances
• Consider CTR degradation over time (typically <10% over 10 years)

Quality and Compliance

• Manufactured under Telefunken's QM-38510 quality system
• 100% electrical testing at production
• Group CTR testing and sorting available
• Hermeticity tested per MIL-STD-883 Method 1014

Revision History

The current datasheet revision is A1, dated 20.09.1995. This revision includes updated CTR grouping specifications and additional reliability test data.