ISO35MDW RS422/RS485 Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO35MDW is a Texas Instruments RS422/RS485 digital isolator rated for 2500Vrms isolation with 3 channels, 1Mbps data rate, and 25kV/µs common mode transient immunity. Packaged in 16-SOIC surface mount configuration, this component is classified as Last Time Buy, indicating end-of-life status. Identifying qualified substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications requiring RS422/RS485 isolated communication interfaces.

Substiute Parts

ISO35MDW

Texas InstrumentsIn Stock: 1234ISO35MDW Datasheet

Current PartRFQ

ISO1410DWR

Texas InstrumentsIn Stock: 5450ISO1410DWR Datasheet

MFR RecommendedRFQ

MAX14945EWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1183MAX14945EWE+ Datasheet

MFR RecommendedRFQ

MAX14945EWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1107MAX14945EWE+T Datasheet

MFR RecommendedRFQ

MAX14948EWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 2501MAX14948EWE+ Datasheet

MFR RecommendedRFQ

MAX14948EWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 27967MAX14948EWE+T Datasheet

MFR RecommendedRFQ

MAX14949EWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1268MAX14949EWE+ Datasheet

MFR RecommendedRFQ

MAX14949EWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 3442MAX14949EWE+T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ISO35MDW is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Package type: 16-SOIC (0.295", 7.50mm Width) surface mount
• Protocol support: RS422/RS485
• Channel configuration: 3 channels with 2/1 input/output arrangement
• Technology: Capacitive coupling isolation
• Isolation voltage: Minimum 2500Vrms (equal or higher acceptable)
• Common mode transient immunity: Minimum 25kV/µs
• Data rate: Minimum 1Mbps (equal or higher acceptable)

Acceptable Parameter Variations:

• Supply voltage ranges may differ if the substitute supports the ISO35MDW operating range
• Operating temperature range may extend beyond the original specification
• Propagation delay and rise/fall time specifications may vary
• Packaging format (Tube, Tape & Reel) does not affect functional compatibility

Substitute parts are grouped by isolation voltage rating, as this parameter directly impacts application safety margins and regulatory compliance.

Parameter Comparison

Engineering Selection Recommendations

ISO1410DWR Consideration: ISO1410DWR is a half-duplex transceiver rather than a digital isolator. It lacks galvanic isolation and operates with a single 1/1 channel configuration, making it unsuitable as a direct functional replacement for the ISO35MDW. This part does not meet the mandatory isolation voltage and channel configuration requirements.

MAX14945EWE+ / MAX14945EWE+T (2750Vrms Isolators): These parts meet all mandatory compatibility criteria with 3-channel configuration, 2/1 channel arrangement, and 2750Vrms isolation exceeding the ISO35MDW minimum. Data rate is reduced to 500kbps, and operating temperature range is limited to -40°C ~ 85°C. These substitutes are suitable for applications where the extended temperature range of the ISO35MDW is not required and lower data rates are acceptable. Both Tube and Tape & Reel packaging options are available.

MAX14948EWE+ / MAX14948EWE+T (5000Vrms Isolators): These parts provide enhanced isolation voltage at 5000Vrms with identical 3-channel, 2/1 configuration. Data rate specification is 500kbps. Operating temperature range is -40°C ~ 85°C. These substitutes offer superior isolation margin and are suitable for high-noise industrial environments. Tape & Reel packaging provides significantly higher inventory availability (27,925 units).

MAX14949EWE+ / MAX14949EWE+T (5000Vrms Isolators): These parts match the MAX14948 series in isolation voltage and channel configuration with 5000Vrms rating and 3-channel, 2/1 arrangement. Data rate is 500kbps with operating temperature -40°C ~ 85°C. Supply voltage range begins at 3V, aligning more closely with the ISO35MDW 3.15V minimum. Both Tube and Tape & Reel options are available.

All substitute parts maintain ROHS3 compliance and active product status, ensuring long-term availability and regulatory alignment.

Frequently Asked Questions (FAQ)

Q: Can ISO1410DWR replace ISO35MDW in my design? A: No. ISO1410DWR is a transceiver without galvanic isolation and features only a single 1/1 channel configuration. It does not provide the 2500Vrms isolation or 3-channel, 2/1 architecture required by the ISO35MDW. This part is not functionally equivalent.

Q: What is the primary difference between MAX14945, MAX14948, and MAX14949 series? A: The primary difference is isolation voltage rating. MAX14945 provides 2750Vrms isolation, while MAX14948 and MAX14949 both provide 5000Vrms isolation. All three maintain identical 3-channel, 2/1 configuration and 500kbps data rate. MAX14949 has a supply voltage range starting at 3V, closer to the ISO35MDW specification.

Q: Why is the data rate reduced in substitute parts? A: The ISO35MDW operates at 1Mbps, while the MAX14945, MAX14948, and MAX14949 series are rated for 500kbps. This is a design characteristic of these substitute isolators. Applications requiring 1Mbps operation must confirm compatibility with the 500kbps specification or identify alternative parts.

Q: Does packaging format affect functional compatibility? A: No. Tube, Tape & Reel (TR), and Cut Tape (CT) packaging formats are logistics and handling variations only. They do not affect electrical performance or functional compatibility. Selection should be based on assembly process requirements and inventory management.

Q: Are all substitute parts RoHS3 compliant? A: Yes. All listed substitute parts maintain ROHS3 compliance, matching the ISO35MDW environmental and regulatory status.

Q: What is the operating temperature limitation of substitute parts? A: The ISO35MDW operates from -55°C ~ 125°C. All substitute parts (MAX14945, MAX14948, MAX14949) operate from -40°C ~ 85°C. Applications requiring operation below -40°C or above 85°C cannot use these substitutes.

Q: Can I use MAX14948EWE+T in place of MAX14948EWE+? A: Yes. Both parts are electrically identical. The difference is packaging format: EWE+ is Tube packaging, while EWE+T is Tape & Reel packaging. Selection depends on assembly process and volume requirements.