ISO7420FED Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO7420FED is a general purpose digital isolator manufactured by Texas Instruments, designed for applications requiring galvanic isolation with 2500Vrms isolation voltage rating. This capacitive coupling technology device operates at 50Mbps data rate with 25kV/µs common mode transient immunity across 2 unidirectional channels in an 8-SOIC surface mount package. The part is currently active in production status with ROHS3 compliance and unlimited moisture sensitivity rating (MSL 1).

Equivalent and substitute parts are identified when design requirements allow for alternative manufacturers or when enhanced performance specifications can be accommodated within the application constraints.

Substiute Parts

ISO7420FED

Texas InstrumentsIn Stock: 2033ISO7420FED Datasheet

Current PartRFQ

ISO7420ED

Texas InstrumentsIn Stock: 2385ISO7420ED Datasheet

Parametric EquivalentRFQ

SI8620BB-B-ISR

Skyworks Solutions Inc.In Stock: 1348SI8620BB-B-ISR Datasheet

MFR RecommendedRFQ

SI8620BC-B-ISR

Skyworks Solutions Inc.In Stock: 36434SI8620BC-B-ISR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the ISO7420FED are identified based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Isolation voltage rating (minimum 2500Vrms required)
• Number of channels (2 channels required)
• Channel configuration (unidirectional required)
• Package type (8-SOIC form factor required)
• Operating temperature range (-40°C ~ 125°C required)
• Supply voltage compatibility (3V ~ 5.5V overlap required)

Substitute Categories:

Parametric Equivalent: ISO7420ED (Texas Instruments) — Identical electrical specifications and performance characteristics to the main part, with different packaging format (Tube vs. Tube).

Enhanced Performance Substitutes: SI8620BB-B-ISR and SI8620BC-B-ISR (Skyworks Solutions Inc.) — These parts exceed the minimum isolation voltage and CMTI requirements while maintaining the same package footprint and channel configuration. The SI8620BC-B-ISR provides 3750Vrms isolation (50% higher than required), while both Skyworks devices offer 150Mbps data rate (3x faster) and 35kV/µs CMTI (40% higher).

Parameter Comparison

Engineering Selection Recommendations

ISO7420ED Selection: This part is a direct parametric equivalent to the ISO7420FED with identical electrical performance. Selection is appropriate when inventory availability or packaging format (Tube) aligns with procurement requirements. Both parts maintain ROHS3 compliance and active production status.

SI8620BB-B-ISR Selection: This Skyworks substitute provides enhanced performance specifications while maintaining compatibility with the ISO7420FED footprint and pinout. The higher data rate (150Mbps vs. 50Mbps) and improved CMTI (35kV/µs vs. 25kV/µs) offer design margin for applications with demanding signal integrity requirements. Supply voltage range extends to 2.5V, enabling operation in lower voltage systems. Moisture sensitivity increases to MSL 2A, requiring controlled storage conditions (4-week floor life limit). ROHS3 compliance is maintained.

SI8620BC-B-ISR Selection: This Skyworks substitute provides the highest isolation voltage rating (3750Vrms) among the available options, delivering 50% additional isolation margin beyond the ISO7420FED specification. Performance enhancements match the SI8620BB-B-ISR (150Mbps data rate, 35kV/µs CMTI). This part is suitable for applications requiring enhanced isolation robustness or operating in high-voltage environments. Moisture sensitivity and compliance certifications match the SI8620BB-B-ISR.

All substitute parts maintain the required 8-SOIC package footprint, unidirectional 2-channel configuration, and -40°C to 125°C operating temperature range.

Frequently Asked Questions (FAQ)

Q: Can SI8620BB-B-ISR or SI8620BC-B-ISR be used as direct drop-in replacements for ISO7420FED?

A: Yes, both Skyworks parts are pin-compatible and functionally compatible replacements. The 8-SOIC package footprint is identical. Enhanced performance specifications (higher data rate, improved CMTI, extended supply voltage range) do not create compatibility issues in applications designed for the ISO7420FED baseline specifications.

Q: What is the difference between SI8620BB-B-ISR and SI8620BC-B-ISR?

A: The primary difference is isolation voltage rating. SI8620BB-B-ISR provides 2500Vrms isolation (matching ISO7420FED), while SI8620BC-B-ISR provides 3750Vrms isolation. All other electrical parameters are identical. Selection depends on application isolation voltage requirements.

Q: Are there supply voltage compatibility concerns when substituting with Skyworks parts?

A: No. The Skyworks SI8620 series supply voltage range (2.5V ~ 5.5V) encompasses the ISO7420FED range (3V ~ 5.5V). Applications operating at 3V or higher will function identically with either manufacturer's device.

Q: What is the impact of MSL 2A moisture sensitivity on the Skyworks substitutes?

A: MSL 2A requires controlled storage with a 4-week floor life limit after package opening. This is more restrictive than the ISO7420FED MSL 1 (unlimited floor life). Procurement and assembly processes must account for this moisture sensitivity level to prevent component degradation.

Q: Do propagation delay differences affect circuit timing?

A: The Skyworks substitutes exhibit 2ns longer propagation delay (13ns vs. 11ns maximum). Applications with tight timing margins must account for this 18% increase in delay. Pulse width distortion also increases from 3ns to 4.5ns. Timing-critical designs should evaluate these parameters against system requirements.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. ISO7420ED, SI8620BB-B-ISR, and SI8620BC-B-ISR all maintain ROHS3 compliance status, matching the ISO7420FED environmental certification.