ISP321-1SM Equivalent & Substitute Parts

Part Overview

The ISP321-1SM is an optoisolator with transistor output manufactured by Isocom Components 2004 LTD. This single-channel device provides 5300Vrms isolation and is designed for DC input applications requiring galvanic isolation in surface mount configurations. The part is Active status and ROHS3 compliant. Substitute parts are identified when equivalent electrical performance and mechanical compatibility are required due to inventory constraints, supply chain considerations, or design flexibility needs.

Substiute Parts

ISP321-1SM

Isocom Components 2004 LTDIn Stock: 1209ISP321-1SM Datasheet

Current PartRFQ

ISP321-1XSM

Isocom Components 2004 LTDIn Stock: 3212ISP321-1XSM Datasheet

Parametric EquivalentRFQ

4N27SM

onsemiIn Stock: 164844N27SM Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the ISP321-1SM are classified into two categories based on parametric equivalence:

Parametric Equivalent (Direct Substitute): ISP321-1XSM matches all critical electrical and mechanical parameters including isolation voltage (5300Vrms), current transfer ratio range (50%-600% @ 5mA), output voltage (80V), output current (50mA), package type (4-SMD), and operating temperature range (-30°C ~ 100°C). This part is functionally interchangeable in all applications.

Similar Substitute (Design Consideration Required): 4N27SM from onsemi provides optoisolator functionality with transistor output but differs in isolation voltage (4170Vrms), package configuration (6-SMD vs 4-SMD), output voltage rating (30V vs 80V), and current transfer ratio specifications. Selection requires design verification for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

ISP321-1XSM is the recommended direct substitute for ISP321-1SM. Both parts are manufactured by Isocom Components 2004 LTD, share identical electrical specifications, and use the same 4-SMD package footprint. Both are Active status and ROHS3 compliant. No design changes are required for PCB layout or circuit operation.

4N27SM is a functional alternative when isolation voltage requirements are 4170Vrms or lower and output voltage is limited to 30V maximum. The 6-SMD package requires PCB footprint modification. This part is manufactured by onsemi and is Active status with ROHS3 compliance. Selection of 4N27SM requires verification that application requirements are met within its specified electrical parameters.

Frequently Asked Questions (FAQ)

Q: Can ISP321-1XSM be used as a direct replacement for ISP321-1SM? A: Yes. ISP321-1XSM is a parametric equivalent with identical isolation voltage (5300Vrms), current transfer ratio (50%-600% @ 5mA), output specifications (80V, 50mA), package type (4-SMD), and operating temperature range (-30°C ~ 100°C). No circuit or layout modifications are required.

Q: What are the key differences between ISP321-1SM and 4N27SM? A: The primary differences are isolation voltage (5300Vrms vs 4170Vrms), output voltage rating (80V vs 30V), package configuration (4-SMD vs 6-SMD), and current transfer ratio specifications. The 4N27SM includes base output while ISP321-1SM does not. These differences require design verification before substitution.

Q: Is the 4N27SM suitable for high-voltage isolation applications? A: The 4N27SM provides 4170Vrms isolation, which is lower than the ISP321-1SM specification of 5300Vrms. Applications requiring 5300Vrms isolation must use ISP321-1SM or ISP321-1XSM.

Q: What PCB layout considerations apply when substituting 4N27SM for ISP321-1SM? A: The 4N27SM uses a 6-SMD Gull Wing package versus the 4-SMD package of ISP321-1SM. PCB footprint, pad spacing, and component placement must be modified to accommodate the different package geometry.

Q: Are all three parts ROHS3 compliant? A: Yes. ISP321-1SM, ISP321-1XSM, and 4N27SM are all ROHS3 compliant and suitable for applications with RoHS requirements.