N05DB3R3M Equivalent & Substitute Parts

Part Overview

The N05DB3R3M is a 3.3 µH fixed unshielded inductor manufactured by Taiyo Yuden, rated for 2.5 A continuous current with a maximum DC resistance of 40 mOhm. This component is designed for surface mount applications in nonstandard package configurations. The part is classified as obsolete, necessitating identification of equivalent substitute components that maintain functional compatibility while offering active product status and improved availability.

Substiute Parts

N05DB3R3M

Taiyo YudenIn Stock: 1041N05DB3R3M Datasheet

Current PartRFQ

7447789003

Würth ElektronikIn Stock: 30597447789003 Datasheet

SimilarRFQ

SDR0603-3R3ML

Bourns Inc.In Stock: 6606SDR0603-3R3ML Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the N05DB3R3M is determined by strict alignment of electrical and mechanical parameters. The primary substitution criteria are:

Critical Parameters for Substitution:

• Inductance value: 3.3 µH (fixed requirement)
• Inductance tolerance: ±20% (must match or be tighter)
• Current rating: minimum 2.5 A (equal or greater acceptable)
• DC resistance: 40 mOhm maximum (lower values acceptable)
• Mounting type: Surface Mount (required)
• Moisture sensitivity: MSL 1 (required)

Secondary Compatibility Factors:

• Operating temperature range must encompass or exceed -25°C ~ 105°C
• Self-resonant frequency: 45 MHz minimum (higher values acceptable)
• Shielding configuration: unshielded preferred for direct replacement; shielded variants acceptable if electrical parameters align

The substitute parts identified below meet these criteria with variations in core material, shielding, and current handling capacity that do not compromise functional compatibility.

Parameter Comparison

Engineering Selection Recommendations

7447789003 (Würth Elektronik WE-PD Robust Series)

This substitute provides superior electrical performance with 3.42 A current rating (36.8% higher than the original specification) and reduced DC resistance of 30 mOhm (25% lower than the original 40 mOhm maximum). The component features shielded drum core construction with ferrite material, resulting in a higher self-resonant frequency of 67 MHz. Operating temperature range extends to -40°C ~ 125°C, exceeding the original specification. The part carries AEC-Q200 automotive qualification and ROHS3 compliance. Physical dimensions are larger (7.30mm x 7.30mm vs. 6.10mm x 5.90mm), requiring verification of board layout compatibility. This option is recommended for applications requiring enhanced thermal performance and automotive-grade reliability.

SDR0603-3R3ML (Bourns Inc. SDR0603 Series)

This substitute maintains unshielded construction identical to the original N05DB3R3M, with ferrite drum core wirewound design. The current rating of 2.2 A is 12% lower than the original specification, making this option suitable only for applications where the 2.5 A rating is not fully utilized. DC resistance of 50 mOhm exceeds the original 40 mOhm maximum by 25%, introducing slightly higher losses. Self-resonant frequency of 68 MHz exceeds the original 45 MHz. Operating temperature range of -40°C ~ 125°C provides extended low-temperature performance. ROHS3 compliance and active product status ensure long-term availability. Physical dimensions of 5.80mm x 5.80mm are comparable to the original, facilitating direct board layout substitution. This option is recommended for space-constrained applications where the lower current rating is acceptable.

Frequently Asked Questions (FAQ)

Q: Can the 7447789003 be used as a direct replacement for the N05DB3R3M?

A: The 7447789003 meets all critical electrical parameters (3.3 µH inductance, ±20% tolerance, MSL 1) and exceeds current rating and temperature range specifications. However, the shielded construction differs from the original unshielded design, and physical dimensions are larger (7.30mm x 7.30mm vs. 6.10mm x 5.90mm). Board layout verification is required before substitution.

Q: Is the SDR0603-3R3ML suitable for all applications using the N05DB3R3M?

A: The SDR0603-3R3ML is suitable for applications where the current requirement does not exceed 2.2 A. The original N05DB3R3M is rated for 2.5 A; therefore, this substitute is not appropriate for designs operating at or near the original current specification. DC resistance is also 25% higher, increasing power dissipation.

Q: What are the key differences between the two substitute options?

A: The 7447789003 offers higher current capacity (3.42 A), lower DC resistance (30 mOhm), shielded construction, and automotive qualification (AEC-Q200). The SDR0603-3R3ML maintains unshielded construction, has lower current capacity (2.2 A), higher DC resistance (50 mOhm), and smaller physical dimensions. Selection depends on application current requirements, EMI considerations, and board space constraints.

Q: Are both substitute parts RoHS compliant?

A: Yes, both the 7447789003 and SDR0603-3R3ML are ROHS3 compliant. The original N05DB3R3M RoHS status is not specified in the provided data.

Q: What is the impact of different shielding configurations?

A: The original N05DB3R3M is unshielded, as is the SDR0603-3R3ML. The 7447789003 features shielded construction, which reduces electromagnetic radiation and susceptibility to external fields. Shielded inductors are beneficial in noise-sensitive applications but may occupy more board space and have different frequency response characteristics.

Q: Can physical dimension differences affect circuit board layout?

A: Yes. The 7447789003 measures 7.30mm x 7.30mm compared to the original 6.10mm x 5.90mm, requiring layout verification. The SDR0603-3R3ML measures 5.80mm x 5.80mm, which is comparable to the original and facilitates direct substitution from a footprint perspective.

Q: What is the significance of the higher self-resonant frequency in the substitute parts?

A: Both substitute parts exhibit higher self-resonant frequencies (67 MHz and 68 MHz respectively) compared to the original 45 MHz. This indicates improved high-frequency performance and reduced parasitic effects at elevated frequencies, which is generally advantageous for broadband applications.

Q: How do operating temperature ranges compare?

A: The original N05DB3R3M operates from -25°C to 105°C. Both substitutes extend the lower temperature limit to -40°C and the upper limit to 125°C, providing wider operational margins for temperature-sensitive applications.