CNW84S Optoisolator Equivalent & Substitute Parts

Part Overview

The CNW84S is an optoisolator with transistor output manufactured by onsemi, designed for high-voltage isolation applications. It features 5900Vrms isolation voltage, single-channel configuration, and surface mount packaging in 6-SMD Gull Wing format. The part is currently classified as obsolete, making identification of suitable substitute components essential for ongoing design support and production continuity.

Substiute Parts

CNW84S

onsemiIn Stock: 781CNW84S Datasheet

Current PartRFQ

CNY17F-2S

Lite-On Inc.In Stock: 1796CNY17F-2S Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CNW84S is determined by the following critical parameters:

• Isolation Voltage: The CNW84S provides 5900Vrms isolation. Substitute parts must maintain isolation voltage at or above this specification to ensure equivalent safety and performance margins.
• Output Configuration: Single-channel transistor output is required for functional equivalence.
• Package Format: 6-SMD Gull Wing surface mount packaging ensures mechanical and electrical compatibility with existing PCB layouts.
• Current Transfer Ratio Range: The CTR specification (0.63% to 3.20% @ 10mA) defines the optical coupling efficiency and must be matched or exceeded by substitute components.
• Output Voltage and Current Ratings: Maximum output voltage of 80V and output current of 100mA per channel establish the load-handling capability.
• Saturation Voltage: Vce saturation of 400mV maximum defines the on-state voltage drop of the output transistor.

The CNY17F-2S from Lite-On Inc. qualifies as a substitute based on these parameters.

Parameter Comparison

Engineering Selection Recommendations

The CNY17F-2S from Lite-On Inc. is the identified substitute for the obsolete CNW84S. Selection of this substitute is supported by the following factors:

• Product Availability: The CNY17F-2S is actively manufactured with 1734 units in stock, ensuring supply continuity for the obsolete CNW84S.
• Regulatory Compliance: The CNY17F-2S is ROHS3 compliant, meeting current environmental and regulatory requirements, whereas the CNW84S is RoHS non-compliant.
• Package Compatibility: Both components use identical 6-SMD Gull Wing surface mount packaging, enabling direct PCB layout compatibility without redesign.
• Electrical Performance: The CNY17F-2S demonstrates superior current transfer ratio performance (63% to 125% versus 0.63% to 3.20%), lower saturation voltage (300mV versus 400mV), and higher output current capability (150mA versus 100mA).
• Isolation Voltage Consideration: The CNY17F-2S provides 5000Vrms isolation, which is 900Vrms lower than the CNW84S specification. Applications requiring the full 5900Vrms isolation margin must evaluate whether the 5000Vrms rating is acceptable for the intended use case.
• Output Voltage Rating: The CNY17F-2S maximum output voltage is 70V compared to 80V for the CNW84S. Applications operating near the 80V limit require verification that 70V is sufficient.

Frequently Asked Questions (FAQ)

Q: Can the CNY17F-2S directly replace the CNW84S without PCB modifications?

A: Yes, the CNY17F-2S uses the same 6-SMD Gull Wing package as the CNW84S, enabling direct pin-compatible substitution on existing PCBs without layout changes.

Q: What is the isolation voltage difference, and does it affect substitution?

A: The CNW84S provides 5900Vrms isolation while the CNY17F-2S provides 5000Vrms. The 900Vrms difference represents approximately 15% lower isolation rating. Applications must verify that 5000Vrms isolation meets the required safety and performance margins for the specific circuit.

Q: How do the current transfer ratios compare?

A: The CNW84S has a CTR range of 0.63% to 3.20% @ 10mA, while the CNY17F-2S has a CTR range of 63% to 125% @ 10mA. The CNY17F-2S exhibits significantly higher optical coupling efficiency, which may require circuit design adjustments if the original design relied on the lower CTR characteristics of the CNW84S.

Q: Are there output voltage or current limitations with the CNY17F-2S?

A: The CNY17F-2S has a maximum output voltage of 70V (versus 80V for the CNW84S) and a maximum output current of 150mA (versus 100mA for the CNW84S). Applications operating at or near the 80V output limit must confirm that 70V is acceptable. The higher current rating of the CNY17F-2S is advantageous for most applications.

Q: What are the compliance differences between these parts?

A: The CNW84S is RoHS non-compliant, while the CNY17F-2S is ROHS3 compliant. For new designs or applications subject to environmental regulations, the CNY17F-2S is the appropriate choice.

Q: Is the CNY17F-2S available in the same packaging options?

A: The CNY17F-2S is supplied in Tube packaging in 6-SMD Gull Wing format, matching the mechanical compatibility of the CNW84S.