SI8431AB-C-ISR Digital Isolator Equivalent & Substitute Parts

Part Overview

The SI8431AB-C-ISR is a general purpose digital isolator manufactured by Skyworks Solutions Inc., featuring 2500Vrms isolation voltage, 3 channels, and 1Mbps data rate in a 16-SOIC package. This device is classified as "Not For New Designs," making identification of active equivalent parts essential for ongoing production and maintenance applications. The SI8631AB-B-IS serves as a direct functional substitute with enhanced specifications and active product status.

Substiute Parts

SI8431AB-C-ISR

Skyworks Solutions Inc.In Stock: 24511SI8431AB-C-ISR Datasheet

Current PartRFQ

SI8631AB-B-IS

Skyworks Solutions Inc.In Stock: 15534SI8631AB-B-IS Datasheet

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Key Parameters

Substitute Part Grouping Explanation

The SI8631AB-B-IS qualifies as a direct substitute for the SI8431AB-C-ISR based on the following critical parameters:

• Identical isolation voltage specification (2500Vrms)
• Matching channel count and configuration (3 channels, 2/1 unidirectional)
• Identical data rate (1Mbps)
• Identical package and pinout (16-SOIC, 0.295" × 7.50mm)
• Identical technology platform (Capacitive Coupling)
• Matching operating temperature range (-40°C ~ 125°C)
• Compatible supply voltage range (SI8631AB-B-IS: 2.5V ~ 5.5V encompasses SI8431AB-C-ISR: 2.7V ~ 5.5V)
• Identical mounting type (Surface Mount)

The SI8631AB-B-IS represents an enhanced variant with improved Common Mode Transient Immunity (35kV/µs vs. 25kV/µs) and faster rise/fall times, while maintaining full backward compatibility.

Parameter Comparison

Engineering Selection Recommendations

The SI8631AB-B-IS is the appropriate selection for applications currently using or specifying the SI8431AB-C-ISR. The substitute part maintains full electrical and mechanical compatibility while offering the following advantages:

• Active product status ensures long-term availability and manufacturing support
• ROHS3 compliance and REACH unaffected status provide regulatory alignment
• Enhanced Common Mode Transient Immunity (35kV/µs) provides improved noise immunity in high-speed switching environments
• Improved rise and fall times (2.5ns symmetric) reduce signal distortion compared to the asymmetric timing of the original part
• Extended lower supply voltage limit (2.5V vs. 2.7V) enables operation in additional low-power applications
• Identical pinout and package eliminate PCB redesign requirements

Frequently Asked Questions (FAQ)

Q: Can SI8631AB-B-IS be used as a direct replacement for SI8431AB-C-ISR without PCB modifications?

A: Yes. Both parts use identical 16-SOIC packaging with matching pinouts, supply voltage ranges, and isolation specifications. No PCB layout changes are required.

Q: What is the difference in packaging between the two parts?

A: SI8431AB-C-ISR is supplied in Tape & Reel format, while SI8631AB-B-IS is supplied in Tube packaging. Both use the same 16-SOIC component package. Packaging format affects handling and storage but not electrical performance or PCB compatibility.

Q: Are there performance differences between these parts?

A: The SI8631AB-B-IS provides enhanced Common Mode Transient Immunity (35kV/µs vs. 25kV/µs) and faster, more symmetric rise and fall times (2.5ns vs. 3.8ns/2.8ns). Propagation delay, pulse width distortion, and data rate remain identical. These improvements represent performance enhancements rather than functional changes.

Q: Why is the SI8431AB-C-ISR marked "Not For New Designs"?

A: This designation indicates the part is in mature or end-of-life status. The SI8631AB-B-IS, marked as Active, is the recommended selection for new designs and ongoing production.

Q: What supply voltage range should be used with SI8631AB-B-IS?

A: The SI8631AB-B-IS operates across 2.5V to 5.5V. Designs currently using 2.7V to 5.5V with the SI8431AB-C-ISR remain fully compatible. The extended lower limit enables additional low-voltage applications.

Q: Are there compliance or certification differences?

A: SI8631AB-B-IS carries ROHS3 compliance and REACH unaffected status. These certifications support modern supply chain and environmental requirements. Compliance information for SI8431AB-C-ISR was not provided in the specification data.