ISO7021FDR Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO7021FDR is a general purpose digital isolator manufactured by Texas Instruments, featuring 3000Vrms isolation voltage, 2-channel unidirectional configuration, and 4Mbps data rate in an 8-SOIC surface mount package. The device is Active product status and ROHS3 compliant. Substitute parts are identified when equivalent electrical performance and mechanical compatibility are required due to inventory constraints, design flexibility, or supply chain considerations.

Substiute Parts

ISO7021FDR

Texas InstrumentsIn Stock: 3927ISO7021FDR Datasheet

Current PartRFQ

ISO7021DR

Texas InstrumentsIn Stock: 1598ISO7021DR Datasheet

Parametric EquivalentRFQ

SI8621AB-B-ISR

Skyworks Solutions Inc.In Stock: 19426SI8621AB-B-ISR Datasheet

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SI8621BC-B-ISR

Skyworks Solutions Inc.In Stock: 9671SI8621BC-B-ISR Datasheet

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SI8621EC-B-ISR

Skyworks Solutions Inc.In Stock: 25135SI8621EC-B-ISR Datasheet

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SI8622BC-B-ISR

Skyworks Solutions Inc.In Stock: 17535SI8622BC-B-ISR Datasheet

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SI8622EC-B-ISR

Skyworks Solutions Inc.In Stock: 35133SI8622EC-B-ISR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts are classified into two categories based on parametric equivalence:

Parametric Equivalent (Direct Substitution): ISO7021DR matches all critical electrical parameters of the ISO7021FDR, including 3000Vrms isolation voltage, 2-channel unidirectional configuration, 4Mbps data rate, 100kV/µs CMTI, and identical package specifications. The only difference is packaging format (Cut Tape & Digi-Reel vs. standard reel configuration). This part is suitable for direct replacement in applications where the ISO7021FDR is specified.

Similar Parts (Application-Dependent Substitution): SI8621AB-B-ISR, SI8621BC-B-ISR, SI8621EC-B-ISR, SI8622BC-B-ISR, and SI8622EC-B-ISR are Skyworks Solutions devices that share the same 8-SOIC package and 2-channel unidirectional topology. However, these parts differ in isolation voltage, data rate, and CMTI specifications. Substitution is permissible only when application requirements allow for these parameter variations.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement: ISO7021DR is the only parametric equivalent to ISO7021FDR. Both devices are Texas Instruments products with Active product status and ROHS3 compliance. Selection between these two is determined by packaging requirements and inventory availability.

Alternative Selection: Skyworks Solutions SI8621 and SI8622 series devices are suitable alternatives when application requirements permit lower isolation voltage (2500Vrms minimum), reduced CMTI (35kV/µs), or higher data rates (150Mbps). All substitute parts maintain 8-SOIC package compatibility, ROHS3 compliance, and Active product status. Operating temperature range differs: Skyworks devices operate from -40°C to 125°C compared to ISO7021FDR's -55°C to 125°C. Supply voltage range for Skyworks devices is 2.5V to 5.5V, excluding the 1.71V to 1.89V range available on Texas Instruments devices.

Frequently Asked Questions (FAQ)

Q: Can ISO7021DR replace ISO7021FDR directly? A: Yes. ISO7021DR is a parametric equivalent with identical electrical specifications, isolation voltage, data rate, CMTI, and package configuration. Substitution is direct.

Q: Are Skyworks SI8621 and SI8622 devices compatible with ISO7021FDR applications? A: Compatibility depends on application requirements. These devices share the same 8-SOIC package and 2-channel unidirectional topology. However, they differ in isolation voltage (3750Vrms vs. 3000Vrms), data rate (150Mbps vs. 4Mbps), and CMTI (35kV/µs vs. 100kV/µs). Applications requiring 3000Vrms isolation or 100kV/µs CMTI cannot use these alternatives.

Q: What is the difference between SI8621 and SI8622 series? A: Both series offer identical electrical specifications (3750Vrms, 150Mbps, 35kV/µs CMTI). The primary difference is packaging format: SI8621BC-B-ISR and SI8621EC-B-ISR are supplied in Cut Tape & Digi-Reel format, while SI8622BC-B-ISR and SI8622EC-B-ISR are supplied in Tape & Reel format.

Q: What is the difference between SI8621BC-B-ISR and SI8621EC-B-ISR? A: Both parts are identical in electrical specifications and package. The difference is in temperature grade designation (B vs. E suffix), which may indicate different qualification or binning criteria from Skyworks Solutions.

Q: Can I use SI8621AB-B-ISR as a substitute? A: SI8621AB-B-ISR has lower isolation voltage (2500Vrms) and lower data rate (1Mbps) compared to ISO7021FDR. Substitution is only permissible if application requirements allow for these reduced specifications.

Q: Are all substitute parts ROHS3 compliant? A: Yes. All listed substitute parts are ROHS3 compliant and have Active product status.

Q: What is the operating temperature difference? A: ISO7021FDR operates from -55°C to 125°C. Skyworks Solutions substitute parts operate from -40°C to 125°C. Applications requiring operation below -40°C must use ISO7021FDR or ISO7021DR.