ISO722MD Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO722MD is a general purpose digital isolator manufactured by Texas Instruments, featuring 2500Vrms isolation voltage, single channel unidirectional operation, and 150Mbps data rate in an 8-SOIC surface mount package. This component is classified as obsolete, necessitating identification of equivalent and substitute parts for ongoing design support and procurement continuity. The ISO722MD utilizes capacitive coupling technology and operates across a 3V to 5.5V supply range with common mode transient immunity of 25kV/µs.

Substiute Parts

ISO722MD

Texas InstrumentsIn Stock: 1509ISO722MD Datasheet

Current PartRFQ

ISO722MDR

Texas InstrumentsIn Stock: 2883ISO722MDR Datasheet

MFR RecommendedRFQ

ISO721MD

Texas InstrumentsIn Stock: 1392ISO721MD Datasheet

Parametric EquivalentRFQ

SI8710CD-B-ISR

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

MFR RecommendedRFQ

SI8717BC-A-IS

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

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ISO722MD is determined by alignment of critical electrical and mechanical parameters. The primary substitution criteria are:

Electrical Parameters:

• Isolation voltage rating (2500Vrms minimum)
• Data rate capability (150Mbps minimum)
• Common mode transient immunity (25kV/µs minimum)
• Supply voltage range compatibility (3V ~ 5.5V)
• Channel configuration (1 channel, unidirectional)
• Operating temperature range (-40°C ~ 125°C)

Mechanical Parameters:

• Package type (8-SOIC preferred for form factor compatibility)
• Surface mount mounting type
• Pin count and pitch alignment

Substitute parts are grouped into two categories: direct replacements maintaining identical electrical specifications and packaging, and parametric equivalents offering enhanced performance characteristics while maintaining functional compatibility within the application envelope.

Parameter Comparison

Engineering Selection Recommendations

ISO722MDR (Manufacturer Recommended Replacement)

The ISO722MDR is the primary recommended substitute for the obsolete ISO722MD. This part maintains identical electrical specifications including 2500Vrms isolation voltage, 150Mbps data rate, 25kV/µs common mode transient immunity, and 3V to 5.5V supply range. The ISO722MDR is packaged in Tape & Reel format rather than Tube, reflecting standard production packaging for active components. The part carries Active product status with ROHS3 compliance and MSL 1 rating, ensuring long-term availability and supply chain stability. Pin-for-pin compatibility and identical package dimensions (8-SOIC, 0.154" width) enable direct board-level substitution without design modification.

ISO721MD (Parametric Equivalent)

The ISO721MD provides parametric equivalence with identical electrical performance across all critical parameters. This part is classified as Last Time Buy, indicating limited future availability. The ISO721MD maintains the same isolation voltage, data rate, CMTI, and supply voltage specifications as the ISO722MD. Selection of ISO721MD should be limited to applications where existing inventory or design documentation specifically references this part number, as the Active status of ISO722MDR provides superior long-term procurement viability.

SI8717BC-A-IS (Enhanced Performance Alternative)

The SI8717BC-A-IS from Skyworks Solutions offers enhanced common mode transient immunity (35kV/µs versus 25kV/µs) and higher isolation voltage (3750Vrms versus 2500Vrms), providing additional margin in noise-sensitive applications. This part maintains the same 8-SOIC package footprint and operating temperature range. The data rate is reduced to 15Mbps, which is acceptable for applications not requiring the full 150Mbps bandwidth of the ISO722MD. Supply voltage range extends to 2.5V minimum, providing broader compatibility with low-voltage systems. MSL 3 rating requires controlled moisture exposure during storage and assembly.

SI8710CD-B-ISR (High Isolation Voltage Alternative)

The SI8710CD-B-ISR provides the highest isolation voltage rating (5000Vrms) among available substitutes, suitable for applications requiring enhanced isolation margins. This part operates at significantly reduced data rate (1Mbps) and features extended supply voltage range (3V to 30V). The package is 6-SOIC format with larger pitch (0.295" width), requiring PCB layout modification. Common mode transient immunity is 20kV/µs, below the ISO722MD specification. Selection is appropriate only for applications where high isolation voltage is the primary requirement and reduced data rate is acceptable.

Frequently Asked Questions (FAQ)

Q: Can ISO722MDR be used as a direct replacement for ISO722MD without PCB modification?

A: Yes. The ISO722MDR maintains identical electrical specifications and 8-SOIC package dimensions. Pin-for-pin compatibility and form factor equivalence enable direct substitution without circuit design or PCB layout changes. The only difference is packaging format (Tape & Reel versus Tube), which does not affect component functionality.

Q: What is the primary reason for substituting the ISO722MD?

A: The ISO722MD is classified as obsolete, meaning the manufacturer has discontinued production and will not accept new orders. ISO722MDR is the active production equivalent with identical specifications, ensuring continued availability and supply chain support.

Q: Are the Skyworks Solutions parts (SI8710CD-B-ISR and SI8717BC-A-IS) compatible with ISO722MD designs?

A: Compatibility depends on application-specific requirements. Both Skyworks parts maintain the same channel configuration, unidirectional operation, and operating temperature range. However, SI8710CD-B-ISR operates at 1Mbps data rate (versus 150Mbps) and requires PCB layout changes due to different package dimensions. SI8717BC-A-IS operates at 15Mbps and maintains the same 8-SOIC footprint but has reduced data rate. Selection requires verification that reduced data rate specifications do not violate system timing requirements.

Q: What is the significance of MSL (Moisture Sensitivity Level) differences between parts?

A: ISO722MD, ISO722MDR, and ISO721MD carry MSL 1 rating, indicating unlimited shelf life without moisture control. SI8710CD-B-ISR and SI8717BC-A-IS carry MSL 3 rating, requiring storage at controlled humidity (≤60% RH) and limiting shelf life to 168 hours after moisture exposure. MSL 3 parts require baking before assembly if moisture absorption occurs. Selection of MSL 1 parts eliminates moisture management requirements during procurement and assembly.

Q: Can ISO721MD be used instead of ISO722MDR?

A: ISO721MD provides identical electrical specifications and is parametrically equivalent. However, ISO721MD is classified as Last Time Buy, indicating the manufacturer will accept orders only until a specified cutoff date, after which the part becomes unavailable. ISO722MDR carries Active status, ensuring indefinite availability. For new designs or long-term production, ISO722MDR is the preferred selection.

Q: What package considerations apply when selecting substitute parts?

A: The ISO722MD, ISO722MDR, ISO721MD, and SI8717BC-A-IS all use 8-SOIC packages with identical 0.154" width and pin pitch, enabling direct PCB substitution. The SI8710CD-B-ISR uses a larger 6-SOIC package (0.295" width), requiring PCB layout modification including pad repositioning and trace routing changes. Package selection should align with existing PCB design constraints.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts (ISO722MDR, ISO721MD, SI8710CD-B-ISR, and SI8717BC-A-IS) carry ROHS3 compliance certification, meeting environmental and hazardous substance restrictions for commercial and industrial applications.

Q: What is the impact of reduced data rate in SI8717BC-A-IS and SI8710CD-B-ISR?

A: SI8717BC-A-IS operates at 15Mbps (90% reduction from 150Mbps) and SI8710CD-B-ISR operates at 1Mbps (99.3% reduction). These reductions are acceptable only in applications where system bandwidth requirements do not exceed the substitute part's data rate specification. Applications requiring high-speed signal isolation (>15Mbps) must use ISO722MDR or ISO722MD equivalents.