IRD3901R Equivalent & Substitute Parts Reference

Part Overview

The IRD3901R is a general-purpose fast recovery rectifier diode manufactured by Vishay General Semiconductor - Diodes Division, rated for 200 V DC reverse voltage and 20 A average rectified current in a DO-203AB (DO-5) stud mount package. This component is classified as obsolete, necessitating identification of active equivalent and substitute parts for ongoing design support and procurement continuity. Substitute parts must maintain electrical compatibility within the specified voltage and current parameters while accommodating mechanical and thermal requirements of the original application.

Substiute Parts

IRD3901R

Vishay General Semiconductor - Diodes DivisionIn Stock: 722IRD3901R Datasheet

Current PartRFQ

1N3901R

Microchip TechnologyIn Stock: 11921N3901R Datasheet

MFR RecommendedRFQ

1N3911AR

Microchip TechnologyIn Stock: 8751N3911AR Datasheet

MFR RecommendedRFQ

1N3911R

Microchip TechnologyIn Stock: 8731N3911R Datasheet

MFR RecommendedRFQ

UES804R

Microchip TechnologyIn Stock: 1123UES804R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the IRD3901R is determined by the following critical parameters:

Mandatory Compatibility Criteria:

• Voltage - DC Reverse (Vr) (Max): Must equal or exceed 200 V
• Mounting Type: Must be Stud Mount to ensure mechanical compatibility
• Package / Case: Must be DO-203AB (DO-5) for physical interchangeability
• Speed Classification: Must be Fast Recovery ≤ 500ns, > 200mA (Io)

Current Rating Consideration:

• The IRD3901R is rated for 20 A average rectified current. Substitute parts rated at 20 A or higher (such as 50 A variants) are electrically compatible and represent performance upgrades with no derating required.

Secondary Parameters:

• Forward voltage (Vf), reverse recovery time (trr), and reverse leakage current are secondary selection factors that may influence thermal performance and switching characteristics but do not preclude substitution when primary criteria are met.

The substitute parts listed below satisfy all mandatory compatibility criteria and are classified as active products with current manufacturing status.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Equivalents):

The 1N3901R (Microchip Technology) is the primary direct equivalent to the IRD3901R. Both parts share identical voltage (200 V), current (20 A), mounting type (Stud Mount), and package (DO-203AB). The 1N3901R is an active product with 1131 units in stock. This part exhibits improved performance characteristics, including lower forward voltage (1.4 V vs. 1.65 V) and faster reverse recovery time (200 ns vs. 350 ns). The 1N3901R is RoHS non-compliant; applications requiring RoHS compliance cannot use this substitute.

Higher Current Alternatives:

The 1N3911R and 1N3911AR (both Microchip Technology) are rated for 50 A average rectified current, representing a 2.5× current capacity increase over the IRD3901R. Both maintain the 200 V reverse voltage rating, DO-203AB package, and stud mount configuration. These parts are suitable for applications where the original 20 A specification provides insufficient margin or where future design upgrades require higher current handling. The 1N3911AR exhibits the fastest reverse recovery time (150 ns) among all listed substitutes. Both are active products with inventory availability (864 and 805 units respectively). RoHS non-compliance applies to both variants.

Limited Information Substitute:

The UES804R (Microchip Technology) is listed as an active substitute but lacks detailed electrical parameter specifications in the provided data. This part cannot be evaluated against the mandatory compatibility criteria and is not recommended for direct substitution without obtaining complete technical documentation.

Compliance Considerations:

The IRD3901R is ROHS3 compliant. All Microchip substitute parts listed are RoHS non-compliant. Applications subject to RoHS regulatory requirements cannot employ these substitutes without design modification or regulatory exemption documentation.

Frequently Asked Questions (FAQ)

Q: Can the 1N3901R directly replace the IRD3901R in existing designs?

A: Yes, the 1N3901R is a direct electrical and mechanical equivalent. Both parts are rated for 200 V reverse voltage, 20 A average rectified current, and use the DO-203AB stud mount package. Physical installation and electrical performance are compatible. However, RoHS compliance status differs; the 1N3901R is non-compliant while the IRD3901R is ROHS3 compliant.

Q: What is the advantage of using 1N3911R or 1N3911AR instead of 1N3901R?

A: The 1N3911R and 1N3911AR are rated for 50 A average rectified current, providing 2.5× the current capacity of the IRD3901R and 1N3901R. These parts are suitable for applications requiring higher current handling or where design margin improvement is necessary. Both maintain the 200 V voltage rating and DO-203AB package. The 1N3911AR offers the fastest reverse recovery time (150 ns) among all listed options.

Q: Are all substitute parts mechanically compatible with the original IRD3901R mounting?

A: Yes. All listed substitute parts (1N3901R, 1N3911R, 1N3911AR) use the DO-203AB (DO-5) stud mount package, ensuring mechanical interchangeability with the IRD3901R. No modifications to mounting hardware or thermal management systems are required.

Q: What does "Fast Recovery ≤ 500ns, > 200mA (Io)" mean?

A: This specification indicates that the diode is classified as a fast recovery rectifier with reverse recovery time not exceeding 500 nanoseconds when switching currents exceed 200 milliamps. All listed parts meet this classification, with actual reverse recovery times ranging from 150 ns to 350 ns depending on the specific part number.

Q: Why is the UES804R listed as a substitute if detailed specifications are unavailable?

A: The UES804R is included in the manufacturer's substitute list for the IRD3901R but lacks complete electrical parameter data in the provided reference. This part cannot be independently verified against mandatory compatibility criteria. Obtain full technical documentation from the manufacturer before considering this part for substitution.

Q: Can I use a 50 A rated diode (1N3911R or 1N3911AR) in a circuit designed for 20 A (IRD3901R)?

A: Yes. A higher current-rated component is electrically compatible with a lower current application. The 50 A parts will operate within their specifications in a 20 A circuit with no derating or performance degradation. This represents a design upgrade with improved current margin.

Q: What is the difference between 1N3911R and 1N3911AR?

A: Both parts are rated for 200 V and 50 A. The primary difference is reverse recovery time: 1N3911AR has 150 ns while 1N3911R has 200 ns. The 1N3911AR offers faster switching characteristics. Both are active products with similar inventory availability.

Q: Are there temperature range differences between the IRD3901R and its substitutes?

A: Yes. The IRD3901R operates from -40°C to 125°C junction temperature. All Microchip substitutes (1N3901R, 1N3911R, 1N3911AR) operate from -65°C to 150°C, providing extended temperature range capability. This represents an advantage for applications requiring operation at lower or higher temperatures.