PM43-3R3M Equivalent & Substitute Parts Reference

Part Overview

The PM43-3R3M is a 3.3 µH unshielded drum core wirewound inductor manufactured by Bourns Inc., rated for 1.44 A with 87mOhm DC resistance. This component operates across -40°C to 100°C and is classified as obsolete product status. Due to its obsolete designation, identifying equivalent and substitute parts is essential for design continuity, procurement flexibility, and long-term supply chain management.

Substiute Parts

PM43-3R3M

Bourns Inc.In Stock: 796PM43-3R3M Datasheet

Current PartRFQ

SDR0403-3R3ML

Bourns Inc.In Stock: 9086SDR0403-3R3ML Datasheet

DirectRFQ

SRR1806-331M

Bourns Inc.In Stock: 787SRR1806-331M Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PM43-3R3M are identified based on the following critical parameters that determine functional equivalence:

Primary Matching Criteria:

• Inductance value: 3.3 µH (±20% tolerance)
• Mounting type: Surface Mount
• Core material: Ferrite
• Package footprint: 4.50mm x 4.00mm x 4.60mm maximum height
• Core configuration: Drum core wirewound

Acceptable Variation Parameters:

• Current rating: Substitute must meet or exceed 1.44 A minimum
• DC resistance: Lower DCR values are acceptable (improved performance)
• Operating temperature: Extended range acceptable
• Shielding: Both shielded and unshielded configurations acceptable for this inductance value
• Product status: Active status preferred for long-term availability

The SDR0403-3R3ML qualifies as a direct substitute based on matching inductance, tolerance, core type, package dimensions, and mounting configuration while providing superior current rating (2.15 A) and lower DCR (58mOhm). The SRR1806-331M does not qualify as a functional substitute due to significantly different inductance value (330 µH vs. 3.3 µH).

Parameter Comparison

Engineering Selection Recommendations

SDR0403-3R3ML is the qualified substitute for PM43-3R3M applications. Selection rationale:

• Identical inductance specification (3.3 µH ±20%)
• Identical package footprint and mounting configuration
• Superior electrical performance: 49% higher current rating (2.15 A vs. 1.44 A) and 33% lower DC resistance (58mOhm vs. 87mOhm)
• Extended operating temperature range (-40°C to 125°C vs. -40°C to 100°C)
• Active product status ensures ongoing availability and supply chain stability
• ROHS3 compliance meets modern regulatory requirements
• Tape & Reel packaging supports automated assembly processes

SRR1806-331M is not suitable as a substitute. The 330 µH inductance value represents a 100x increase from the required 3.3 µH specification and is incompatible with circuit designs requiring the original inductance value.

Frequently Asked Questions (FAQ)

Q: Can SDR0403-3R3ML be used as a direct replacement for PM43-3R3M?

A: Yes. Both components share identical inductance (3.3 µH), tolerance (±20%), core type (ferrite drum core), shielding configuration (unshielded), and package footprint (4.50mm x 4.00mm x 4.60mm). The SDR0403-3R3ML provides improved electrical performance with higher current rating and lower DC resistance.

Q: What are the key differences between PM43-3R3M and SDR0403-3R3ML?

A: The primary differences are product status (obsolete vs. active), current rating (1.44 A vs. 2.15 A), DC resistance (87mOhm vs. 58mOhm), operating temperature range (-40°C to 100°C vs. -40°C to 125°C), RoHS compliance status, and packaging format. Functionally, both components are equivalent for 3.3 µH inductance applications.

Q: Why is SRR1806-331M listed but not recommended as a substitute?

A: SRR1806-331M has a fundamentally different inductance value (330 µH) compared to the required 3.3 µH specification. This 100-fold difference makes it unsuitable for circuits designed around the PM43-3R3M. Additionally, its larger package footprint (18.30mm x 14.00mm x 7.10mm) is incompatible with the original component's PCB layout.

Q: Are there any compatibility concerns when switching from PM43-3R3M to SDR0403-3R3ML?

A: No compatibility concerns exist for standard applications. Both components are surface mount inductors with identical inductance and package dimensions. The SDR0403-3R3ML's superior current rating and lower DC resistance provide performance benefits without introducing compatibility issues.

Q: What is the significance of RoHS compliance differences?

A: PM43-3R3M is RoHS non-compliant, while SDR0403-3R3ML is ROHS3 compliant. For new designs or applications subject to RoHS regulations, SDR0403-3R3ML is the appropriate selection. For legacy systems without RoHS requirements, both components are functionally equivalent.

Q: Does the extended temperature range of SDR0403-3R3ML affect circuit performance?

A: The extended operating range (-40°C to 125°C vs. -40°C to 100°C) provides additional design margin and environmental flexibility. For applications operating within the original PM43-3R3M temperature range, this difference has no negative impact.