CNY74 Optocoupler Technical Summary

Overview

The CNY74-2 and CNY74-4 are optocoupler devices consisting of a phototransistor optically coupled to a gallium arsenide (GaAs) infrared emitting diode. These components are housed in an 8-lead (CNY74-2) or 16-lead (CNY74-4) plastic dual inline package (DIP). The CNY74 series provides electrical isolation between input and output circuits, making them ideal for applications requiring signal isolation, noise immunity, and voltage level translation.

These optocouplers are designed for high reliability and performance in industrial, automotive, and telecommunications applications. The devices feature low coupling capacitance, high current transfer ratio (CTR), and a wide operating temperature range, ensuring stable performance under varying environmental conditions.

Features

• Multiple Channel Options: The CNY74-2 includes 2 isolator channels, while the CNY74-4 includes 4 isolator channels.
• High Isolation Voltage: DC isolation test voltage (V_IO) of 2.5 kV, ensuring robust electrical isolation.
• Compliance with Standards: Test class 25/100/21 DIN 40 045 compliant.
• Low Coupling Capacitance: Typical value of 0.3 pF, minimizing noise and crosstalk.
• High Current Transfer Ratio (CTR): Typical CTR of 100%, ensuring efficient signal transmission.
• Stable Performance: Low temperature coefficient of CTR for consistent operation across temperature variations.
• Wide Operating Temperature Range: Suitable for use in harsh environments.

Applications

The CNY74 optocouplers are versatile components suitable for a wide range of applications, including:

• Industrial Control Systems: Isolate high-voltage circuits from low-voltage control logic.
• Telecommunications: Provide signal isolation in communication interfaces to prevent ground loops and noise interference.
• Automotive Electronics: Ensure reliable signal transmission in vehicle control systems.
• Medical Equipment: Isolate sensitive circuits from high-voltage sections in medical devices.
• Power Supply Monitoring: Detect and isolate faults in power supply circuits.
• Digital Logic Isolation: Interface between different voltage domains in digital systems.

Electrical Characteristics

Absolute Maximum Ratings

The following table outlines the absolute maximum ratings for a single coupled system. Exceeding these values may cause permanent damage to the device.

• Reverse Voltage (V_R): 6 V
• Forward Current (I_F): 60 mA

Recommended Operating Conditions

For optimal performance, operate the CNY74 within the following conditions:

• Forward Current (I_F): 10 mA to 50 mA
• Collector-Emitter Voltage (V_CE): Up to 30 V
• Ambient Temperature Range: -40°C to +85°C

Current Transfer Ratio (CTR)

The CTR is a key parameter indicating the efficiency of the optocoupler. The CNY74 series offers a typical CTR of 100%, ensuring minimal signal loss across the isolation barrier.

Package Information

CNY74-2 (8-Lead DIP)

The CNY74-2 is housed in an 8-lead plastic dual inline package (DIP). The pin connections are as follows:

• Pin 1: Anode of IR Emitter (Channel 1)
• Pin 2: Cathode of IR Emitter (Channel 1)
• Pin 3: Not Connected
• Pin 4: Emitter of Phototransistor (Channel 1)
• Pin 5: Collector of Phototransistor (Channel 1)
• Pin 6: Collector of Phototransistor (Channel 2)
• Pin 7: Emitter of Phototransistor (Channel 2)
• Pin 8: Cathode of IR Emitter (Channel 2)

CNY74-4 (16-Lead DIP)

The CNY74-4 is housed in a 16-lead plastic dual inline package (DIP). The pin connections are as follows:

• Pin 1: Anode of IR Emitter (Channel 1)
• Pin 2: Cathode of IR Emitter (Channel 1)
• Pin 3: Not Connected
• Pin 4: Emitter of Phototransistor (Channel 1)
• Pin 5: Collector of Phototransistor (Channel 1)
• Pin 6: Collector of Phototransistor (Channel 2)
• Pin 7: Emitter of Phototransistor (Channel 2)
• Pin 8: Cathode of IR Emitter (Channel 2)
• Pin 9: Anode of IR Emitter (Channel 3)
• Pin 10: Cathode of IR Emitter (Channel 3)
• Pin 11: Not Connected
• Pin 12: Emitter of Phototransistor (Channel 3)
• Pin 13: Collector of Phototransistor (Channel 3)
• Pin 14: Collector of Phototransistor (Channel 4)
• Pin 15: Emitter of Phototransistor (Channel 4)
• Pin 16: Cathode of IR Emitter (Channel 4)

Conclusion

The CNY74-2 and CNY74-4 optocouplers are robust, high-performance components designed for applications requiring electrical isolation and noise immunity. With features such as high isolation voltage, low coupling capacitance, and a wide temperature range, these devices are well-suited for industrial, automotive, and telecommunications applications. Their multiple channel options and reliable performance make them a versatile choice for designers seeking to enhance system safety and signal integrity.