RSFML Equivalent & Substitute Parts

Part Overview

The RSFML is a general-purpose rectifier diode rated for 1000 V DC reverse voltage with 500 mA average rectified current in a Sub SMA surface mount package. This component is classified as "Not For New Designs," indicating it has reached end-of-life status. Identifying equivalent and substitute parts is necessary to support existing designs, maintain production continuity, and ensure long-term component availability for legacy applications.

Substiute Parts

RSFML

Taiwan Semiconductor CorporationIn Stock: 7690RSFML Datasheet

Current PartRFQ

RS1MLW

Taiwan Semiconductor CorporationIn Stock: 20477RS1MLW Datasheet

MFR RecommendedRFQ

RSFML R3G

Taiwan Semiconductor CorporationIn Stock: 665RSFML R3G Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the RSFML are classified into two categories based on electrical and mechanical compatibility:

Parametric Equivalent (RSFML R3G): This part maintains identical electrical specifications and package form factor. All critical parameters—reverse voltage, average rectified current, forward voltage, reverse recovery time, reverse leakage current, and junction temperature range—are matched to the original RSFML. The package remains DO-219AB (Sub SMA). This classification applies when all allowed electrical and mechanical parameters are equivalent.

Manufacturer Recommended Substitute (RS1MLW): This part shares the same reverse voltage rating (1000 V) and forward voltage characteristic (1.3 V @ rated current) but differs in current capacity (1 A versus 500 mA), reverse recovery time (250 ns versus 500 ns), and package form factor (SOD-123W versus Sub SMA). This substitute is applicable in designs where the higher current rating and improved recovery speed provide functional compatibility despite the package change.

Substitution eligibility is determined by:

• Voltage - DC Reverse (Vr) (Max) compatibility
• Current - Average Rectified (Io) capability
• Voltage - Forward (Vf) (Max) @ If matching
• Reverse Recovery Time (trr) performance
• Package / Case physical compatibility
• Operating Temperature - Junction range

Parameter Comparison

Engineering Selection Recommendations

RSFML R3G (Parametric Equivalent): Select this part for direct replacement in existing designs. All electrical parameters and the package form factor are identical to the original RSFML. The part is in Active product status, ensuring long-term availability and supply chain stability. Full compliance with ROHS3, REACH, and MSL 1 certifications is maintained. No circuit modifications or PCB layout changes are required.

RS1MLW (Recommended Substitute): Select this part when the original RSFML is unavailable and the design can accommodate a package change from Sub SMA (DO-219AB) to SOD-123W. This substitute provides higher current capacity (1 A versus 500 mA) and faster reverse recovery time (250 ns versus 500 ns), which may improve circuit performance in applications operating below the original 500 mA specification. The part is in Active product status with identical voltage ratings and forward voltage characteristics. Extended junction temperature range (-55°C to 175°C versus -55°C to 150°C) provides additional thermal margin. Full compliance with ROHS3, REACH, and MSL 1 certifications is maintained. PCB layout modification is required due to package form factor change.

Frequently Asked Questions (FAQ)

Q: Can RSFML R3G be used as a direct replacement for RSFML?

A: Yes. RSFML R3G is a parametric equivalent with identical electrical specifications and package form factor. No circuit modifications or PCB layout changes are required. Both parts maintain the same voltage rating (1000 V), current rating (500 mA), forward voltage (1.3 V @ 500 mA), and reverse recovery time (500 ns).

Q: What is the primary difference between RSFML R3G and RS1MLW?

A: RSFML R3G maintains the original Sub SMA package (DO-219AB), while RS1MLW uses the SOD-123W package. Additionally, RS1MLW has higher current capacity (1 A versus 500 mA) and faster reverse recovery time (250 ns versus 500 ns). Both share the same 1000 V reverse voltage rating and 1.3 V forward voltage characteristic.

Q: Can RS1MLW be used in place of RSFML without circuit modifications?

A: RS1MLW can be used functionally in place of RSFML if the design operates at or below 500 mA. However, the package change from Sub SMA to SOD-123W requires PCB layout modification. The higher current rating and faster recovery time of RS1MLW are compatible with RSFML applications but do not require circuit redesign.

Q: Why is RSFML marked as "Not For New Designs"?

A: This status indicates the part has reached end-of-life. RSFML R3G and RS1MLW are active alternatives that provide equivalent or enhanced functionality for both legacy support and new design applications.

Q: Are all three parts compliant with environmental and regulatory standards?

A: Yes. RSFML, RSFML R3G, and RS1MLW are all ROHS3 compliant, REACH unaffected, and rated MSL 1 (unlimited moisture sensitivity). All parts meet the same environmental and regulatory requirements.

Q: What is the impact of the package change from Sub SMA to SOD-123W?

A: The package change affects PCB footprint, land pattern, and assembly process. SOD-123W is a standard surface mount package with different dimensional specifications than Sub SMA (DO-219AB). PCB layout and assembly documentation must be updated to accommodate the new package form factor.

Q: Does RS1MLW have a higher operating temperature range than RSFML?

A: Yes. RS1MLW operates from -55°C to 175°C, while RSFML operates from -55°C to 150°C. This provides an additional 25°C of upper temperature margin, which may be beneficial in thermally demanding applications.

Q: Are there any performance advantages to using RS1MLW over RSFML R3G?

A: RS1MLW offers faster reverse recovery time (250 ns versus 500 ns) and higher current capacity (1 A versus 500 mA). These characteristics may reduce switching losses and provide additional design margin in high-frequency or high-current applications. However, these advantages require package change and PCB modification.