SI8631ET-AS Digital Isolator Equivalent & Substitute Parts

Part Overview

The SI8631ET-AS is an automotive-grade general purpose digital isolator manufactured by Skyworks Solutions Inc. This device provides 5000Vrms isolation across 3 channels with 150Mbps data rate capability and 60kV/µs common mode transient immunity. The part operates across the automotive temperature range of -40°C to 125°C and meets AEC-Q100 qualification requirements.

The SI8631ET-AS is classified as Active product status. Substitute parts are identified when inventory constraints, lead time requirements, or application-specific channel count needs necessitate alternative component selection while maintaining electrical and mechanical compatibility within defined parameters.

Substiute Parts

SI8631ET-AS

Skyworks Solutions Inc.In Stock: 1147SI8631ET-AS Datasheet

Current PartRFQ

SI8610BD-B-IS

Skyworks Solutions Inc.In Stock: 1335SI8610BD-B-IS Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the SI8631ET-AS is based on the following critical parameters that must remain constant or compatible:

Mandatory Matching Parameters:

• Voltage - Isolation: 5000Vrms (electrical isolation barrier requirement)
• Package / Case: 16-SOIC (0.295", 7.50mm Width) (mechanical and PCB layout compatibility)
• Technology: Capacitive Coupling (internal architecture compatibility)
• Voltage - Supply: 2.5V ~ 5.5V (power supply compatibility)
• Operating Temperature: -40°C ~ 125°C (automotive temperature range)
• Grade: Automotive (application classification)
• Data Rate: 150Mbps (signal integrity and timing requirements)

Allowable Variation Parameters:

• Number of Channels: May vary based on application requirements
• Common Mode Transient Immunity (CMTI): May be lower in substitute parts
• Propagation Delay and Pulse Width Distortion: Remain consistent across the SI86xx family

The SI8610BD-B-IS qualifies as a parametric equivalent substitute based on matching all mandatory parameters while differing only in channel count (1 channel versus 3 channels) and CMTI specification (35kV/µs versus 60kV/µs).

Parameter Comparison

Engineering Selection Recommendations

SI8631ET-AS Selection Criteria:

• Applications requiring 3-channel isolation with 2 inputs on Side 1 and 1 input on Side 2
• Systems demanding 60kV/µs common mode transient immunity
• Designs with AEC-Q100 qualification requirement explicitly stated
• Automotive applications operating across -40°C to 125°C temperature range

SI8610BD-B-IS Selection Criteria:

• Applications requiring single-channel isolation only
• Systems where 35kV/µs common mode transient immunity is sufficient
• Inventory or lead time constraints requiring alternative sourcing
• Identical PCB footprint and electrical interface requirements (16-SOIC package, 5000Vrms isolation, 150Mbps data rate)
• Automotive temperature range compatibility (-40°C to 125°C)

Substitution Constraints: The SI8610BD-B-IS cannot substitute the SI8631ET-AS in applications requiring simultaneous 3-channel isolation or the higher 60kV/µs CMTI specification. Channel count reduction and CMTI specification reduction must be evaluated against specific application requirements before substitution.

Frequently Asked Questions (FAQ)

Q: Can SI8610BD-B-IS replace SI8631ET-AS in all applications?

A: No. The SI8610BD-B-IS provides only 1 channel of isolation compared to the SI8631ET-AS 3-channel configuration. Substitution is valid only for applications requiring single-channel isolation. Additionally, the CMTI specification is reduced from 60kV/µs to 35kV/µs.

Q: Are the package dimensions identical between these parts?

A: Yes. Both parts use 16-SOIC (0.295", 7.50mm Width) packaging. PCB footprint and land pattern compatibility are identical, allowing direct physical substitution at the component level.

Q: What is the isolation voltage rating for both parts?

A: Both SI8631ET-AS and SI8610BD-B-IS provide 5000Vrms isolation voltage rating, meeting automotive high-voltage isolation requirements.

Q: Do both parts operate across the same temperature range?

A: Yes. Both parts operate from -40°C to 125°C, covering the full automotive temperature specification.

Q: What is the data rate capability for both isolators?

A: Both parts support 150Mbps data rate with identical propagation delay (13ns maximum for both tpLH and tpHL) and pulse width distortion (4.5ns maximum).

Q: Are the supply voltage requirements the same?

A: Yes. Both parts operate with supply voltage range of 2.5V to 5.5V, providing compatibility with standard automotive power supply architectures.

Q: What does the channel count difference mean for circuit design?

A: The SI8631ET-AS provides 3 independent isolation channels (2 inputs on Side 1, 1 input on Side 2), while SI8610BD-B-IS provides only 1 channel (1 input on Side 1, 0 inputs on Side 2). Applications requiring multiple isolated signal paths must use SI8631ET-AS or multiple SI8610BD-B-IS devices.

Q: How does CMTI specification affect substitution?

A: Common Mode Transient Immunity (CMTI) measures the isolator's ability to maintain signal integrity during rapid voltage transitions across the isolation barrier. SI8631ET-AS specifies 60kV/µs while SI8610BD-B-IS specifies 35kV/µs. Applications with high dV/dt switching events may require the higher CMTI rating of SI8631ET-AS.

Q: Are moisture sensitivity levels identical?

A: Yes. Both parts carry MSL 2A (4 Weeks) rating, indicating identical moisture handling and storage requirements.