CNY17F4S

Overview

The CNY17F4S is a single-channel transistor output optocoupler manufactured by Fairchild Semiconductor. It features an NPN phototransistor output and provides high isolation voltage of 5300 Vrms. The device operates within a temperature range of -55°C to +100°C. Key electrical parameters include a minimum collector-emitter breakdown voltage of 70 V, a maximum collector dark current of 50 nA, and a nominal current transfer ratio of 40%. The component is housed in a 6-SMD surface-mount package.

Feature Summary

• Provides galvanic isolation between input and output circuits using infrared LED and phototransistor technology.
• Designed for surface-mount assembly with a compact 6-SMD footprint.
• Offers high insulation voltage capability for safety-critical applications.

Applications

• Power supply feedback loops
• Signal isolation in industrial control systems
• Microcontroller interface circuits

Procurement Notes

Verify the specific manufacturer source, as Fairchild Semiconductor assets were acquired by onsemi. Confirm that the part number corresponds to the original Fairchild specification sheet rather than a generic equivalent. Ensure the 6-SMD package variant matches the required PCB layout. Check for RoHS compliance documentation if environmental regulations apply to the final assembly.

Selection Notes

Select this component when a surface-mount solution is required for single-channel isolation with moderate speed requirements. The 5300 Vrms rating suits applications needing robust barrier protection. Compare the 40% CTR against system drive capabilities to ensure sufficient output saturation. Verify thermal management needs within the specified operating temperature range.

Part Context

This device belongs to the CNY17 family of phototransistor optocouplers, which are widely used for general-purpose isolation. The 'F' suffix typically denotes a specific current transfer ratio bin or packaging variation compared to standard CNY17 models. These components are commonly found in legacy power supply designs and consumer electronics requiring basic signal separation.

Replacement Considerations

Check for equivalents from onsemi, which acquired Fairchild's semiconductor business. Other manufacturers offer similar 6-SMD transistor output optocouplers with comparable isolation ratings. Ensure pinout compatibility and verify that the replacement meets the same 5300 Vrms insulation requirement.