SI8421AB-C-IS Equivalent & Substitute Parts

Part Overview

The SI8421AB-C-IS is a General Purpose Digital Isolator manufactured by Skyworks Solutions Inc., featuring 2500Vrms isolation voltage and 2-channel unidirectional isolation in an 8-SOIC package. This component is classified as "Not For New Designs," indicating it has reached end-of-life status. Finding equivalent and substitute parts is necessary for ongoing system support, legacy design maintenance, and procurement continuity when original inventory becomes unavailable.

Substiute Parts

SI8421AB-C-IS

Skyworks Solutions Inc.In Stock: 5242SI8421AB-C-IS Datasheet

Current PartRFQ

SI8421AB-D-IS

Skyworks Solutions Inc.In Stock: 2780SI8421AB-D-IS Datasheet

DirectRFQ

SI8410AB-D-IS

Skyworks Solutions Inc.In Stock: 1222SI8410AB-D-IS Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SI8421AB-C-IS is determined by the following critical parameters:

Direct Substitutes (Identical Electrical and Mechanical Specifications):

• Isolation voltage: 2500Vrms
• Number of channels: 2
• Channel configuration: Unidirectional (1 input per side)
• Data rate: 1Mbps
• CMTI: 25kV/µs (Typ)
• Package: 8-SOIC (0.154", 3.90mm Width)
• Supply voltage range: 2.7V ~ 5.5V
• Operating temperature: -40°C ~ 125°C

Parametric Equivalents (Different Channel Count):

• Parts with identical isolation voltage, CMTI, data rate, package, and supply specifications but different channel configurations (1 channel instead of 2) are classified as parametric equivalents. These require design modification to accommodate the reduced channel count.

Parameter Comparison

Engineering Selection Recommendations

SI8421AB-D-IS (Direct Substitute): This part is a direct electrical and mechanical equivalent to the SI8421AB-C-IS. Both components share identical isolation voltage (2500Vrms), channel configuration (2 channels), CMTI (25kV/µs Typ), data rate (1Mbps), package (8-SOIC), supply voltage range (2.7V ~ 5.5V), and operating temperature range (-40°C ~ 125°C). The SI8421AB-D-IS maintains ROHS3 compliance and identical MSL rating. This substitute requires no design modification and provides pin-for-pin compatibility.

SI8410AB-D-IS (Parametric Equivalent): This part is a parametric equivalent with identical electrical performance characteristics (isolation voltage, CMTI, data rate, timing parameters, supply voltage, and operating temperature) but differs in channel count (1 channel versus 2 channels). The SI8410AB-D-IS is suitable only for applications requiring single-channel isolation. Design modification is required to accommodate the reduced channel configuration. This part maintains ROHS3 compliance and identical MSL rating.

Both substitute parts carry "Not For New Designs" status, consistent with the original component. Selection should be based on channel count requirements and design constraints.

Frequently Asked Questions (FAQ)

Q: Can SI8421AB-D-IS be used as a direct replacement for SI8421AB-C-IS? A: Yes. The SI8421AB-D-IS is a direct substitute with identical electrical specifications, channel configuration, package, and compliance certifications. No design modification is required.

Q: What is the difference between SI8421AB-C-IS and SI8410AB-D-IS? A: The primary difference is channel count. The SI8421AB-C-IS provides 2 isolated channels, while the SI8410AB-D-IS provides 1 isolated channel. All other electrical parameters (isolation voltage, CMTI, data rate, timing, supply voltage, and operating temperature) are identical. The SI8410AB-D-IS requires design modification to accommodate single-channel operation.

Q: Are all three parts pin-compatible? A: SI8421AB-C-IS and SI8421AB-D-IS are pin-compatible. The SI8410AB-D-IS has a different pin configuration due to its single-channel design and is not pin-compatible with the 2-channel variants.

Q: Do these parts meet RoHS compliance? A: Yes. All three parts (SI8421AB-C-IS, SI8421AB-D-IS, and SI8410AB-D-IS) are ROHS3 compliant.

Q: What is the moisture sensitivity level for these components? A: All three parts have a Moisture Sensitivity Level (MSL) rating of 2A with a 4-week floor life. Proper handling and storage procedures must be followed to maintain component reliability.

Q: Why is the SI8421AB-C-IS marked "Not For New Designs"? A: This designation indicates the component has reached end-of-life status. While existing inventory remains available, Skyworks Solutions Inc. does not recommend this part for new design implementations. For new designs, consult current product datasheets and availability from the manufacturer.