CNW136S Equivalent & Substitute Parts

Part Overview

The CNW136S is an optoisolator transistor with base output manufactured by onsemi, designed for high-voltage isolation applications requiring 5000Vrms isolation rating. This component features a single channel configuration with transistor output and integrated base connection, suitable for DC input applications with maximum output voltage of 20V and 10mA output current per channel.

The CNW136S is classified as obsolete. Locating equivalent substitute parts is necessary to maintain design continuity and ensure component availability for new production runs, repairs, and system upgrades where this optoisolator function remains required.

Substiute Parts

CNW136S

onsemiIn Stock: 1002CNW136S Datasheet

Current PartRFQ

HCPL4503M

onsemiIn Stock: 6122HCPL4503M Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CNW136S are identified based on strict electrical and mechanical compatibility criteria. The following parameters define acceptable substitution:

Critical Matching Parameters:

• Voltage - Isolation: 5000Vrms (must match exactly)
• Number of Channels: 1 (must match exactly)
• Output Type: Transistor with Base (must match exactly)
• Current Transfer Ratio (Min): 19% @ 16mA (must meet or exceed)
• Input Type: DC (must match exactly)
• Voltage - Output (Max): 20V (must meet or exceed)

Acceptable Variation Parameters:

• Mounting Type: May differ (Surface Mount to Through Hole conversion acceptable with appropriate adapter or PCB redesign)
• Package / Case: May differ if electrical specifications remain compatible
• Current - Output / Channel: May be lower than original if application requirements permit

The HCPL4503M qualifies as a direct substitute based on matching all critical electrical parameters while offering improved specifications in current transfer ratio range and operating temperature definition.

Parameter Comparison

Engineering Selection Recommendations

The HCPL4503M is the qualified substitute for the obsolete CNW136S based on the following engineering criteria:

Electrical Compatibility: All critical electrical parameters match or exceed the CNW136S specification. The 5000Vrms isolation voltage, single-channel configuration, transistor-with-base output topology, and DC input type are identical. The minimum current transfer ratio of 19% @ 16mA is maintained, with the HCPL4503M additionally providing a defined maximum ratio of 50% @ 16mA for improved design predictability.

Output Current Consideration: The HCPL4503M specifies 8mA maximum output current per channel compared to the CNW136S 10mA rating. This substitution is valid only if the application circuit design does not require the full 10mA output current. Circuit analysis must confirm that 8mA output current is sufficient for the intended load.

Compliance Status: The HCPL4503M is ROHS3 compliant and currently in active production, addressing both the obsolescence issue of the CNW136S and modern regulatory compliance requirements. The CNW136S is RoHS non-compliant, making the HCPL4503M preferable for new designs subject to RoHS regulations.

Packaging and Mounting: The HCPL4503M uses through-hole 8-DIP packaging versus the CNW136S surface-mount 8-SMD configuration. This difference requires PCB layout modification and assembly process changes. Through-hole mounting may offer advantages in manual rework and repair scenarios but requires design accommodation.

Availability: The HCPL4503M is in active production with substantial inventory availability, ensuring reliable component sourcing compared to the obsolete CNW136S.

Frequently Asked Questions (FAQ)

Q: Can the HCPL4503M directly replace the CNW136S without any circuit modifications?

A: Electrical substitution is direct based on matching isolation voltage, channel count, output type, and current transfer ratio specifications. However, the different mounting technology (through-hole versus surface-mount) requires PCB redesign. Additionally, the reduced output current specification (8mA versus 10mA) must be verified as acceptable for the application circuit.

Q: What is the impact of the 8mA versus 10mA output current difference?

A: The HCPL4503M maximum output current is 8mA per channel. If the application circuit is designed to operate within 8mA output current limits, substitution is valid. If the circuit requires the full 10mA output current capability, the HCPL4503M may not be suitable. Circuit analysis of the load impedance and required output current is necessary to confirm compatibility.

Q: Does the HCPL4503M meet modern compliance requirements?

A: Yes. The HCPL4503M is ROHS3 compliant, meeting current regulatory requirements for restricted substances. The CNW136S is RoHS non-compliant, making the HCPL4503M the appropriate choice for designs subject to RoHS regulations or modern procurement standards.

Q: What are the packaging implications of switching from 8-SMD to 8-DIP?

A: The CNW136S uses surface-mount 8-SMD gull-wing packaging for automated assembly. The HCPL4503M uses through-hole 8-DIP packaging requiring manual insertion or different automated assembly equipment. PCB footprint redesign is required, and assembly process changes may be necessary. Through-hole components offer advantages in manual rework and repair but require different manufacturing accommodation.

Q: Is the HCPL4503M available in surface-mount packaging?

A: The provided data specifies the HCPL4503M in 8-DIP through-hole packaging only. If surface-mount packaging is required to avoid PCB redesign, alternative optoisolator models with 5000Vrms isolation, single-channel transistor-with-base output, and surface-mount packaging should be evaluated.

Q: What is the significance of the defined operating temperature range in the HCPL4503M?

A: The HCPL4503M specifies an operating temperature range of -40°C to 100°C. The CNW136S does not provide an operating temperature specification. The defined range in the HCPL4503M allows for precise thermal design verification and ensures predictable performance across the specified temperature envelope.

Q: Are there any timing specification differences between these parts?

A: The HCPL4503M specifies turn-on and turn-off times of 250ns and 260ns respectively. The CNW136S does not provide timing specifications. If the application circuit has timing-critical requirements, the HCPL4503M timing specifications must be verified as compatible with the circuit design.