SI8421BB-C-IS Equivalent & Substitute Parts

Part Overview

The SI8421BB-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 device is marked 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 component procurement when original stock becomes unavailable.

Substiute Parts

SI8421BB-C-IS

Skyworks Solutions Inc.In Stock: 2553SI8421BB-C-IS Datasheet

Current PartRFQ

SI8421BB-D-IS

Skyworks Solutions Inc.In Stock: 7009SI8421BB-D-IS Datasheet

DirectRFQ

SI8410BB-D-IS

Skyworks Solutions Inc.In Stock: 1513SI8410BB-D-IS Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SI8421BB-C-IS is determined by the following critical parameters:

Direct Manufacturer Equivalent: SI8421BB-D-IS maintains identical electrical specifications including 2500Vrms isolation, 2-channel configuration, 150Mbps data rate, and 25kV/µs CMTI. The primary difference is packaging variant (tube vs. alternative supplier packaging). This part is functionally interchangeable at the circuit level.

Parametric Equivalent: SI8410BB-D-IS shares the same isolation voltage (2500Vrms), data rate (150Mbps), CMTI (25kV/µs), supply voltage range, operating temperature, and package footprint. The key difference is channel count: SI8410BB-D-IS provides 1 channel versus 2 channels in the SI8421BB-C-IS. This part is suitable only for applications requiring single-channel isolation.

Cross-Manufacturer Alternatives: The substitute list includes Texas Instruments ISO7420 series parts (ISO7420FCCD, ISO7420DR, ISO7420MD, ISO7420MDR, ISO7420D), which maintain equivalent isolation voltage, data rate, and package compatibility but originate from a different manufacturer.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: SI8421BB-D-IS is the primary substitute when component availability or procurement requirements necessitate a change from SI8421BB-C-IS. Both parts carry "Not For New Designs" status and share identical electrical performance. SI8421BB-D-IS provides ROHS3 compliance documentation, which may be required for certain applications or supply chain requirements.

For Single-Channel Applications: SI8410BB-D-IS is suitable only when the application circuit requires single-channel isolation. The reduction from 2 channels to 1 channel represents a functional change and is not a direct replacement for dual-channel designs. This part also provides ROHS3 compliance.

For Legacy System Support: All three Skyworks parts maintain the same isolation voltage, data rate, CMTI, and thermal operating range, ensuring compatibility with existing PCB layouts and circuit designs that use the 8-SOIC footprint.

Frequently Asked Questions (FAQ)

Q: Can SI8421BB-D-IS be used as a direct replacement for SI8421BB-C-IS?

A: Yes. Both parts are manufactured by Skyworks Solutions Inc. and provide identical electrical specifications: 2500Vrms isolation, 2-channel configuration, 150Mbps data rate, 25kV/µs CMTI, and 8-SOIC packaging. The primary difference is packaging variant and RoHS compliance documentation.

Q: What is the key difference between SI8421BB-C-IS and SI8410BB-D-IS?

A: SI8410BB-D-IS provides 1 isolated channel, while SI8421BB-C-IS provides 2 isolated channels. All other electrical parameters remain identical. SI8410BB-D-IS is not a direct replacement for dual-channel applications.

Q: Are the 8-SOIC packages physically identical between these parts?

A: Yes. All three parts use the 8-SOIC (0.154", 3.90mm Width) package, ensuring identical PCB footprint compatibility and pin assignments for the same channel configuration.

Q: What does "Not For New Designs" status mean for these parts?

A: This designation indicates the parts have reached end-of-life status and are no longer recommended for new product development. However, they remain available for legacy system support and maintenance applications.

Q: Does SI8421BB-D-IS provide better compliance than SI8421BB-C-IS?

A: SI8421BB-D-IS includes documented ROHS3 and REACH compliance status, whereas SI8421BB-C-IS does not specify these certifications. For applications requiring regulatory compliance documentation, SI8421BB-D-IS provides explicit certification records.