CNW85S Equivalent & Substitute Parts

Part Overview

The CNW85S is an optoisolator transistor with base output manufactured by onsemi, designed for DC input applications requiring galvanic isolation up to 5900Vrms. This component features a single channel configuration in a 6-SMD surface mount package with a maximum output voltage of 80V and 100mA output current capability. The CNW85S is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing system support and new design implementations.

Substiute Parts

CNW85S

onsemiIn Stock: 1115CNW85S Datasheet

Current PartRFQ

CNY171SM

Fairchild SemiconductorIn Stock: 2598CNY171SM Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CNW85S is determined by the following critical parameters that must be maintained or exceeded:

• Isolation Voltage: Minimum 5900Vrms required for equivalent isolation performance
• Output Configuration: Transistor with base output topology
• Number of Channels: Single channel
• Package Type: 6-SMD, Gull Wing surface mount
• Input Type: DC input
• Output Voltage Rating: Minimum 80V capability
• Output Current: Minimum 100mA per channel
• Vce Saturation: Maximum 400mV

The CNY171SM from Fairchild Semiconductor is identified as a substitute part. However, this part exhibits reduced isolation voltage (4170Vrms versus 5900Vrms) and reduced output current capability (50mA versus 100mA), indicating it functions as a partial substitute suitable only for applications with lower isolation and current requirements.

Parameter Comparison

Engineering Selection Recommendations

The CNW85S is obsolete, necessitating component substitution for ongoing production and field replacement scenarios. The CNY171SM is the identified substitute part and is currently in active production status with 2551 units in stock.

Selection of CNY171SM as a substitute requires verification that the application can tolerate the following deviations from the original CNW85S specification:

• Isolation voltage reduced from 5900Vrms to 4170Vrms
• Maximum output voltage reduced from 80V to 70V
• Maximum output current per channel reduced from 100mA to 50mA

The CNY171SM demonstrates superior current transfer ratio performance (40–80% versus 0.63–3.20%), which may provide improved switching characteristics in applications with adequate isolation and current margins. Both parts share identical Vce saturation specifications (400mV maximum) and package configuration (6-SMD, Gull Wing).

The CNY171SM carries ECCN EAR99 and HTSUS 8541.49.8000 classifications, consistent with the original part. Operating temperature range for CNY171SM is specified as −40°C to 100°C.

Frequently Asked Questions (FAQ)

Q: Can CNY171SM directly replace CNW85S in all applications?

A: No. The CNY171SM has reduced isolation voltage (4170Vrms versus 5900Vrms), reduced maximum output voltage (70V versus 80V), and reduced output current capability (50mA versus 100mA). Substitution is valid only for applications where these reduced specifications remain within system requirements.

Q: What is the primary advantage of CNY171SM over CNW85S?

A: The CNY171SM exhibits significantly higher current transfer ratio (40–80% versus 0.63–3.20%), resulting in improved switching speed and reduced input current requirements. Turn-on and turn-off times are specified as 2µs and 3µs respectively, with rise and fall times of 4µs and 4.6µs maximum.

Q: Are the packages identical between CNW85S and CNY171SM?

A: Yes. Both components use 6-SMD, Gull Wing surface mount packaging, enabling direct PCB footprint compatibility without layout modifications.

Q: What is the inventory status of these parts?

A: CNW85S is obsolete with 1039 units in stock. CNY171SM is active production with 2551 units in stock, providing reliable long-term availability.

Q: Are there compliance differences between CNW85S and CNY171SM?

A: CNW85S is RoHS non-compliant. CNY171SM compliance status is not specified in available data. Both parts carry identical ECCN (EAR99) and HTSUS (8541.49.8000) classifications.