ISO721MD Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO721MD is a general purpose digital isolator manufactured by Texas Instruments, featuring 2500Vrms isolation voltage, 1 channel unidirectional configuration, and 150Mbps data rate in an 8-SOIC package. This device is currently in Last Time Buy status, indicating end-of-life production. Alternative equivalent and substitute parts are necessary for ongoing design support, inventory replenishment, and long-term product availability.

Substiute Parts

ISO721MD

Texas InstrumentsIn Stock: 1392ISO721MD Datasheet

Current PartRFQ

ISO721MDR

Texas InstrumentsIn Stock: 5500ISO721MDR Datasheet

MFR RecommendedRFQ

ISO722MD

Texas InstrumentsIn Stock: 1509ISO722MD Datasheet

Parametric EquivalentRFQ

SI8610AB-B-ISR

Skyworks Solutions Inc.In Stock: 4240SI8610AB-B-ISR Datasheet

MFR RecommendedRFQ

SI8610BC-B-ISR

Skyworks Solutions Inc.In Stock: 6105SI8610BC-B-ISR Datasheet

MFR RecommendedRFQ

SI8610EC-B-ISR

Skyworks Solutions Inc.In Stock: 8036SI8610EC-B-ISR Datasheet

MFR RecommendedRFQ

SI8710CD-B-ISR

Skyworks Solutions Inc.In Stock: 8568SI8710CD-B-ISR Datasheet

MFR RecommendedRFQ

SI8715BC-A-IS

Skyworks Solutions Inc.In Stock: 5337SI8715BC-A-IS Datasheet

MFR RecommendedRFQ

SI8715BC-A-ISR

Skyworks Solutions Inc.In Stock: 2095SI8715BC-A-ISR Datasheet

MFR RecommendedRFQ

SI8716BC-A-IS

Skyworks Solutions Inc.In Stock: 779SI8716BC-A-IS Datasheet

MFR RecommendedRFQ

SI8717BC-A-IS

Skyworks Solutions Inc.In Stock: 901SI8717BC-A-IS Datasheet

MFR RecommendedRFQ

SI8718BC-A-ISR

Skyworks Solutions Inc.In Stock: 1044SI8718BC-A-ISR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ISO721MD is determined by the following critical parameters:

Primary Substitution Criteria:

• Isolation voltage rating (minimum 2500Vrms required)
• Number of channels (1 channel, unidirectional)
• Package type (8-SOIC form factor)
• Data rate capability (minimum 150Mbps)
• Supply voltage compatibility (3V ~ 5.5V range)
• Operating temperature range (-40°C ~ 125°C)

Substitution Categories:

Direct Equivalent (Same Manufacturer): ISO721MDR is the active production equivalent from Texas Instruments with identical electrical specifications and packaging, differing only in packaging format (Cut Tape & Digi-Reel vs. Tube).

Parametric Equivalent (Same Manufacturer): ISO722MD provides identical electrical performance but is marked Obsolete. This part maintains all critical parameters including 2500Vrms isolation, 150Mbps data rate, and 8-SOIC packaging.

Cross-Manufacturer Substitutes (Skyworks Solutions): SI8610BC-B-ISR, SI8610EC-B-ISR, SI8715BC-A-ISR, SI8716BC-A-IS, and SI8717BC-A-IS are functionally compatible alternatives. These parts maintain the 8-SOIC package, unidirectional 1-channel configuration, and operating temperature range. Isolation voltage ratings range from 3750Vrms to 5000Vrms, exceeding the 2500Vrms requirement. Data rates and CMTI specifications vary within acceptable ranges for general purpose applications.

Limited Compatibility Substitute: SI8710CD-B-ISR differs in package format (6-SOIC vs. 8-SOIC) and supply voltage range (3V ~ 30V), requiring PCB layout modification and voltage regulation review.

Lower Performance Substitute: SI8610AB-B-ISR operates at 1Mbps data rate, significantly below the 150Mbps specification, suitable only for low-speed isolation applications.

Parameter Comparison

Engineering Selection Recommendations

Recommended Primary Substitute: ISO721MDR is the preferred replacement for ISO721MD. Both parts are manufactured by Texas Instruments with identical electrical specifications, operating temperature range, and package configuration. ISO721MDR maintains Active product status with higher inventory availability (5400 pcs vs. 1355 pcs). The only difference is packaging format; ISO721MDR is supplied in Cut Tape & Digi-Reel format instead of Tube, which is standard for high-volume production environments.

Recommended Secondary Substitute: SI8610BC-B-ISR and SI8610EC-B-ISR from Skyworks Solutions provide full performance compatibility with the ISO721MD. Both parts deliver 150Mbps data rate in 8-SOIC packaging with Active product status. The higher isolation voltage rating (3750Vrms vs. 2500Vrms) provides additional safety margin. Supply voltage range extends to 2.5V minimum, offering broader application flexibility. Moisture sensitivity level is 2A (4 Weeks) compared to MSL 1 for the original part.

Alternative Substitutes for Lower-Speed Applications: SI8715BC-A-ISR, SI8716BC-A-IS, and SI8717BC-A-IS are suitable for applications where 15Mbps data rate is acceptable. These parts maintain 8-SOIC packaging and Active product status with higher isolation voltage (3750Vrms). Propagation delay is higher (50ns vs. 16ns), which may impact timing-critical circuits.

Not Recommended for Direct Substitution: SI8610AB-B-ISR operates at 1Mbps, insufficient for 150Mbps applications. SI8710CD-B-ISR requires PCB redesign due to different package format (6-SOIC) and extended supply voltage range (3V ~ 30V).

All recommended substitutes maintain ROHS3 compliance, REACH unaffected status, and EAR99 export classification consistent with the original ISO721MD.

Frequently Asked Questions (FAQ)

Q: Can ISO721MDR be used as a direct replacement for ISO721MD?

A: Yes. ISO721MDR is the active production equivalent with identical electrical specifications, isolation voltage, data rate, package type, and operating temperature range. The only difference is packaging format (Cut Tape & Digi-Reel vs. Tube). Both are suitable for the same circuit applications without design modification.

Q: What are the key differences between SI8610BC-B-ISR and ISO721MD?

A: SI8610BC-B-ISR maintains the same 150Mbps data rate and 8-SOIC package as ISO721MD. The isolation voltage is higher (3750Vrms vs. 2500Vrms), and the minimum supply voltage is lower (2.5V vs. 3V). Common mode transient immunity is higher (35kV/µs vs. 25kV/µs). Propagation delay is faster (13ns vs. 16ns). These differences represent performance improvements suitable for direct substitution.

Q: Why is SI8710CD-B-ISR not recommended as a direct substitute?

A: SI8710CD-B-ISR uses a different package format (6-SOIC vs. 8-SOIC), requiring PCB layout modification. The data rate is significantly lower (1Mbps vs. 150Mbps), making it unsuitable for high-speed applications. The supply voltage range is extended (3V ~ 30V), which may require different voltage regulation design.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed maintain ROHS3 compliance, consistent with the original ISO721MD specification.

Q: What is the impact of different moisture sensitivity levels?

A: ISO721MD has MSL 1 (Unlimited), while Skyworks Solutions substitutes have MSL 2A (4 Weeks) or MSL 3 (168 Hours). Lower MSL ratings require stricter moisture control during storage and handling. MSL 2A parts must be used within 4 weeks of package opening; MSL 3 parts within 168 hours. This affects supply chain management and inventory practices.

Q: Can SI8715BC-A-ISR replace ISO721MD in all applications?

A: SI8715BC-A-ISR is suitable for applications where 15Mbps data rate is acceptable. The 150Mbps ISO721MD cannot be replaced by the 15Mbps SI8715BC-A-ISR in high-speed isolation circuits. However, for low-speed applications, SI8715BC-A-ISR provides higher isolation voltage (3750Vrms) and improved common mode transient immunity (35kV/µs).

Q: What is the inventory status for recommended substitutes?

A: ISO721MDR has 5400 pcs in stock. SI8610BC-B-ISR has 4167 pcs. SI8610EC-B-ISR has 7998 pcs. SI8715BC-A-ISR (Tape & Reel) has 2000 pcs. These inventory levels support production requirements for the recommended substitutes.