IS281B Optoisolator Transistor Output Equivalent & Substitute Parts

Part Overview

The IS281B is an optoisolator with transistor output manufactured by Isocom Components 2004 LTD. This single-channel device provides 3750Vrms isolation and is designed for DC input applications requiring galvanic isolation with transistor-based switching output. The part is currently active in production with 4200 units in stock. Substitute parts are identified when equivalent electrical performance and mechanical compatibility are maintained across the specified parameter range, enabling component procurement flexibility and supply chain continuity.

Substiute Parts

IS281B

Isocom Components 2004 LTDIn Stock: 4221IS281B Datasheet

Current PartRFQ

IS281BL

Isocom Components 2004 LTDIn Stock: 1786IS281BL Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the IS281B are identified based on strict equivalence across critical electrical and mechanical parameters. The substitution criteria are:

Electrical Parameters (Must Match):

• Voltage - Isolation: 3750Vrms
• Number of Channels: 1
• Current Transfer Ratio range: 130% (Min) to 260% (Max) @ 5mA
• Output Type: Transistor
• Voltage - Output (Max): 80V
• Current - Output / Channel: 50mA
• Vce Saturation (Max): 200mV
• Input Type: DC

Mechanical & Environmental Parameters (Must Match):

• Mounting Type: Surface Mount
• Operating Temperature: -55°C ~ 110°C
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited)

Package Compatibility:

• Primary package: 4-SOIC (0.173", 4.40mm Width)
• Acceptable variant: 4-SOP (functionally equivalent footprint)

The IS281BL meets all substitution criteria and is classified as a parametric equivalent within the IS281 series.

Parameter Comparison

Engineering Selection Recommendations

Both IS281B and IS281BL are active production parts manufactured by Isocom Components 2004 LTD with identical electrical specifications and environmental compliance certifications. Selection between these parts is based on availability and supply chain requirements rather than technical performance differences.

IS281B is the primary specification with 4200 units in current inventory.

IS281BL is the parametric equivalent substitute with 1764 units in current inventory, belonging to the IS281 series designation.

Both parts maintain ROHS3 compliance and REACH unaffected status, meeting regulatory requirements for industrial and commercial applications. The identical electrical performance across isolation voltage, current transfer ratio, output characteristics, and thermal operating range ensures direct functional interchangeability in circuit designs.

Frequently Asked Questions (FAQ)

Q: Can IS281BL be used as a direct replacement for IS281B?

A: Yes. The IS281BL is a parametric equivalent substitute. All electrical parameters including isolation voltage (3750Vrms), current transfer ratio (130%-260% @ 5mA), output voltage (80V max), output current (50mA), and saturation voltage (200mV max) are identical. Both parts use the same 4-SOIC package and operate across the identical temperature range (-55°C to 110°C).

Q: Are there package differences between IS281B and IS281BL?

A: Both parts use the 4-SOIC (0.173", 4.40mm Width) package. The IS281BL supplier device package designation is listed as 4-SOP, which is functionally equivalent to the 4-SOIC standard and maintains identical PCB footprint compatibility.

Q: What are the key parameters that determine substitutability?

A: Substitutability is determined by matching isolation voltage (3750Vrms), channel count (1), current transfer ratio range (130%-260% @ 5mA), transistor output type, maximum output voltage (80V), maximum output current (50mA), saturation voltage (200mV), operating temperature range (-55°C to 110°C), and surface mount package configuration. All these parameters are identical between IS281B and IS281BL.

Q: Do both parts meet the same compliance standards?

A: Yes. Both IS281B and IS281BL are ROHS3 compliant, REACH unaffected, and carry MSL 1 (Unlimited) moisture sensitivity rating. Both are active production parts with identical regulatory status.

Q: Which part should be selected based on availability?

A: Selection should be based on current inventory levels and project delivery requirements. IS281B has 4200 units in stock, while IS281BL has 1764 units available. Both are functionally equivalent for circuit design purposes.