4N28S(TA) Optoisolator Equivalent & Substitute Parts

Part Overview

The 4N28S(TA) is an optoisolator transistor with base output manufactured by Everlight Electronics Co Ltd. This component provides 5000Vrms isolation voltage in a 6-SMD surface mount package and is designed for applications requiring galvanic isolation with transistor output capability. The part maintains Active product status with 1113 units in current inventory stock.

Substitute parts are identified when equivalent functional performance can be achieved within the allowed electrical and mechanical parameter ranges for optoisolator transistor devices. Substitution becomes necessary due to supply availability, lead time requirements, or inventory constraints while maintaining circuit compatibility.

Substiute Parts

4N28S(TA)

Everlight Electronics Co LtdIn Stock: 12204N28S(TA) Datasheet

Current PartRFQ

4N28SM

onsemiIn Stock: 28004N28SM Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 4N28S(TA) are identified based on the following critical parameters that define functional equivalence:

Primary Substitution Criteria:

• Output Type: Transistor with Base (required match)
• Package / Case: 6-SMD, Gull Wing (required match)
• Mounting Type: Surface Mount (required match)
• Number of Channels: 1 (required match)
• Input Type: DC (required match)
• Current Transfer Ratio (Min): 10% @ 10mA (required match)
• Vce Saturation (Max): 500mV (required match)
• Maximum Forward Current: 60 mA (required match)
• RoHS Status: ROHS3 Compliant (required match)
• Moisture Sensitivity Level: 1 (Unlimited) (required match)

Secondary Substitution Parameters (allowable variation):

• Isolation Voltage: Minimum 4170Vrms (not less than 83% of main part specification)
• Maximum Output Voltage: Minimum 30V (not less than 37.5% of main part specification)
• Operating Temperature Range: Minimum -40°C to 100°C (subset of main part range acceptable)
• Turn On / Turn Off Time: Variation acceptable within component class specifications

The 4N28SM from onsemi qualifies as a substitute part based on these criteria.

Parameter Comparison

Engineering Selection Recommendations

4N28SM (onsemi) as Substitute:

The 4N28SM qualifies as a functional substitute for the 4N28S(TA) based on matching core electrical and mechanical parameters. Both components maintain Active product status and ROHS3 compliance, ensuring regulatory alignment and supply chain continuity.

Application Constraints:

The 4N28SM operates with reduced isolation voltage (4170Vrms versus 5000Vrms) and lower maximum output voltage (30V versus 80V). Circuit designs must confirm that these reduced specifications remain within application requirements. The 4N28SM operates within a narrower temperature range (-40°C to 100°C versus -55°C to 110°C), requiring verification that the application's thermal environment falls within this window.

Electrical Performance:

Both parts share identical current transfer ratio specifications (10% @ 10mA), maximum forward current (60 mA), and Vce saturation characteristics (500mV maximum). The 4N28SM exhibits faster switching performance (2µs turn-on/off versus 3µs), which may provide operational advantages in high-frequency applications.

Packaging and Manufacturing:

Both components use identical 6-SMD surface mount packaging with gull wing leads, ensuring direct PCB footprint compatibility without layout modifications.

Frequently Asked Questions (FAQ)

Q: Can the 4N28SM directly replace the 4N28S(TA) in all applications?

A: The 4N28SM is electrically compatible for applications where the isolation voltage requirement does not exceed 4170Vrms and the maximum output voltage does not exceed 30V. Applications designed for the full 5000Vrms isolation specification of the 4N28S(TA) require circuit-level verification before substitution.

Q: What are the key differences between these two optoisolators?

A: The primary differences are isolation voltage (5000Vrms versus 4170Vrms), maximum output voltage (80V versus 30V), operating temperature range (-55°C to 110°C versus -40°C to 100°C), and switching speed (3µs versus 2µs). All other critical parameters including package type, current transfer ratio, and saturation voltage are identical.

Q: Are the PCB footprints identical?

A: Yes. Both the 4N28S(TA) and 4N28SM use 6-SMD surface mount packaging with gull wing leads. No PCB layout modifications are required for physical substitution.

Q: Does the 4N28SM meet the same compliance standards?

A: Yes. Both components are ROHS3 compliant and carry Moisture Sensitivity Level 1 (Unlimited), ensuring equivalent regulatory and environmental compliance.

Q: What should be verified before substituting the 4N28SM for the 4N28S(TA)?

A: Verify that the application's isolation voltage requirement does not exceed 4170Vrms, the maximum output voltage does not exceed 30V, and the operating temperature range remains within -40°C to 100°C. Confirm that the faster switching speed (2µs) of the 4N28SM does not introduce timing conflicts in the circuit design.

Q: Is the 4N28SM available in the same packaging options?

A: The 4N28SM is supplied in Tube packaging, while the 4N28S(TA) packaging specification is not detailed. Both components use identical 6-SMD surface mount package geometry, ensuring mechanical compatibility regardless of supply packaging format.