ISO15MDW RS422/RS485 Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO15MDW 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 designated as Last Time Buy status, indicating end-of-life production. Identifying qualified substitute parts ensures design continuity and supply chain reliability for applications requiring RS422/RS485 isolated communication interfaces.

Substiute Parts

ISO15MDW

Texas InstrumentsIn Stock: 1169ISO15MDW 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 of the ISO15MDW is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Package / Case: 16-SOIC (0.295", 7.50mm Width) — all substitutes must match this footprint
• Type: RS422/RS485 protocol support — required for functional equivalence
• Number of Channels: 3 channels with 2/1 input configuration — maintains circuit topology
• Channel Type: Unidirectional — preserves signal direction architecture
• Technology: Capacitive Coupling — isolation method consistency

Performance Parameters Allowing Substitution:

• Voltage - Isolation: Minimum 2500Vrms (substitutes with equal or higher ratings are acceptable)
• Common Mode Transient Immunity: Minimum 25kV/µs (substitutes with equal or higher ratings are acceptable)
• Data Rate: Minimum 1Mbps (substitutes with equal or higher rates are acceptable)
• Voltage - Supply: Must support the application's supply voltage range
• Operating Temperature: Must encompass the application's operating range

Compliance Requirements:

• RoHS3 Compliant status required
• Surface Mount mounting type required

The substitute parts listed below meet these criteria with variations in isolation voltage, CMTI rating, data rate, and supply voltage specifications that allow functional replacement in the ISO15MDW application.

Parameter Comparison

Engineering Selection Recommendations

ISO1410DWR Consideration: The ISO1410DWR is a Texas Instruments RS422/RS485 transceiver with 1/1 channel configuration and half-duplex operation. This part differs fundamentally from the ISO15MDW in channel count (1 vs. 3) and input configuration (1/1 vs. 2/1), making it unsuitable as a direct substitute for applications requiring the 3-channel, 2/1 unidirectional architecture of the ISO15MDW.

MAX14945EWE+ and MAX14945EWE+T (Analog Devices/Maxim): These parts provide 2750Vrms isolation with 35kV/µs CMTI, exceeding the ISO15MDW's 2500Vrms and 25kV/µs specifications. Data rate is reduced to 500kbps. Operating temperature range is -40°C to 85°C, which is narrower than the ISO15MDW's -55°C to 125°C. Supply voltage compatibility spans 1.71V to 5.5V. Both parts maintain Active product status and ROHS3 compliance. The EWE+ variant uses Tube packaging; the EWE+T variant uses Tape & Reel packaging.

MAX14948EWE+ and MAX14948EWE+T (Analog Devices/Maxim): These parts provide 5000Vrms isolation with 35kV/µs CMTI, significantly exceeding the ISO15MDW specifications. Data rate is 500kbps. Operating temperature range is -40°C to 85°C. Supply voltage compatibility spans 1.71V to 5.5V. Propagation delay specifications are provided (1.04µs max). Both parts maintain Active product status and ROHS3 compliance with MSL 1 (Unlimited). The EWE+ variant uses Tube packaging; the EWE+T variant uses Tape & Reel packaging with highest inventory availability (27,925 pcs).

MAX14949EWE+ and MAX14949EWE+T (Analog Devices/Maxim): These parts provide 5000Vrms isolation with 35kV/µs CMTI. Data rate is 500kbps. Operating temperature range is -40°C to 85°C. Supply voltage compatibility spans 3V to 5.5V, which overlaps with the ISO15MDW's 3.15V to 3.6V range. Both parts maintain Active product status and ROHS3 compliance with MSL 1 (Unlimited). The EWE+ variant uses Tube packaging; the EWE+T variant packaging is not specified.

Selection Basis: All substitute parts listed maintain the mandatory 16-SOIC package footprint, 3-channel configuration with 2/1 input topology, unidirectional channel type, and capacitive coupling technology. Substitutes with higher isolation voltage and CMTI ratings provide enhanced performance margins. Selection should account for application-specific requirements regarding data rate (1Mbps vs. 500kbps), operating temperature range (-55°C to 125°C vs. -40°C to 85°C), and supply voltage compatibility. Active product status ensures ongoing availability and manufacturing support compared to the ISO15MDW's Last Time Buy designation.

Frequently Asked Questions (FAQ)

Q: Can the ISO1410DWR replace the ISO15MDW? A: No. The ISO1410DWR is a 1-channel half-duplex transceiver with 1/1 input configuration, whereas the ISO15MDW is a 3-channel unidirectional digital isolator with 2/1 input configuration. These architectural differences prevent functional equivalence.

Q: What is the primary difference between MAX14945 and MAX14948 series? A: The MAX14945 series provides 2750Vrms isolation, while the MAX14948 series provides 5000Vrms isolation. Both maintain 35kV/µs CMTI and 500kbps data rate. Selection depends on application isolation voltage requirements.

Q: Why is the ISO15MDW's data rate (1Mbps) higher than substitute parts (500kbps)? A: The ISO15MDW operates at 1Mbps, while all listed substitutes operate at 500kbps. Applications requiring 1Mbps data rates must verify that 500kbps operation is acceptable, or alternative parts outside this substitute list must be evaluated.

Q: What is the significance of operating temperature range differences? A: The ISO15MDW operates from -55°C to 125°C, while Analog Devices/Maxim substitutes operate from -40°C to 85°C. Applications requiring operation below -40°C or above 85°C cannot use the listed Maxim substitutes. The ISO1410DWR supports -40°C to 125°C, covering the upper temperature range of the ISO15MDW.

Q: Are packaging variants (Tube vs. Tape & Reel) functionally equivalent? A: Yes. Tube and Tape & Reel packaging variants of the same part number (e.g., MAX14948EWE+ vs. MAX14948EWE+T) are functionally identical. Packaging selection is determined by assembly process requirements and volume considerations.

Q: What does MSL 1 (Unlimited) mean compared to MSL 2 (1 Year)? A: MSL 1 (Unlimited) indicates the component has unlimited shelf life under controlled storage conditions. MSL 2 (1 Year) requires use within one year of manufacture under controlled conditions. Maxim substitutes offer superior moisture sensitivity performance.

Q: Can I use a substitute with higher isolation voltage than required? A: Yes. Higher isolation voltage ratings provide additional safety margin and are acceptable for applications requiring lower isolation voltages. The ISO15MDW's 2500Vrms requirement is satisfied by substitutes rated at 2750Vrms or 5000Vrms.

Q: What does ROHS3 Compliant status indicate? A: ROHS3 Compliant indicates the component meets Restriction of Hazardous Substances Directive requirements, restricting lead, cadmium, mercury, and other hazardous materials. All listed parts maintain this compliance.