CD43NP-3R9MC Equivalent & Substitute Parts

Part Overview

The CD43NP-3R9MC is a 3.9 µH unshielded ferrite core inductor manufactured by Sumida America Components Inc. This surface mount component is rated for 1.84 A continuous current with a maximum DC resistance of 93.7 mOhm. The part operates across the temperature range of -40°C to 100°C and is RoHS3 compliant with MSL 1 rating. As an active product with 7800 units in stock, the CD43NP-3R9MC serves applications requiring compact, fixed inductance in the 3.9 µH range. Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the specified parameter tolerances.

Substiute Parts

CD43NP-3R9MC

Sumida America Components Inc.In Stock: 7893CD43NP-3R9MC Datasheet

Current PartRFQ

SDR0403-3R9ML

Bourns Inc.In Stock: 10406SDR0403-3R9ML Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CD43NP-3R9MC is determined by strict equivalence across the following critical parameters:

Inductance Value: The substitute part must maintain 3.9 µH inductance within the ±20% tolerance band specified for the original component.

Current Rating: The substitute must support a minimum continuous current rating of 1.84 A. Parts with higher current ratings are acceptable as they provide equal or superior performance margin.

DC Resistance: The substitute's maximum DC resistance must not exceed 93.7 mOhm to ensure equivalent power dissipation characteristics and thermal performance.

Core Material: Both parts must use ferrite core construction to maintain consistent magnetic properties and frequency response.

Shielding Configuration: Both parts must be unshielded to preserve electromagnetic coupling characteristics in the application circuit.

Mounting and Package: Surface mount configuration with identical physical dimensions (4.50mm L x 4.00mm W x 3.50mm H) ensures mechanical compatibility with existing PCB layouts.

Compliance and Environmental: Both parts must maintain RoHS3 compliance and MSL 1 rating for manufacturing process compatibility.

The SDR0403-3R9ML from Bourns Inc. meets all substitution criteria within these parameters.

Parameter Comparison

Engineering Selection Recommendations

The SDR0403-3R9ML qualifies as a direct substitute for the CD43NP-3R9MC based on the following engineering criteria:

Electrical Equivalence: Both inductors maintain identical 3.9 µH inductance with ±20% tolerance. The substitute's 1.98 A current rating exceeds the original 1.84 A requirement, providing additional design margin. The substitute's 76 mOhm maximum DC resistance is lower than the original 93.7 mOhm specification, resulting in reduced power dissipation and improved thermal performance.

Mechanical Compatibility: Identical surface mount package dimensions (4.50mm L x 4.00mm W x 3.50mm H) ensure direct PCB layout compatibility without redesign.

Compliance and Manufacturing: Both parts maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity rating, ensuring compatibility with standard manufacturing processes and supply chain requirements.

Environmental Performance: The substitute's extended operating temperature range (-40°C to 125°C) provides broader environmental coverage compared to the original (-40°C to 100°C).

Inventory and Availability: The substitute part (SDR0403-3R9ML) has 10300 units in stock, providing supply security for production requirements.

Frequently Asked Questions (FAQ)

Q: Can the SDR0403-3R9ML be used as a direct replacement for CD43NP-3R9MC in existing designs?

A: Yes. Both inductors share identical inductance (3.9 µH), tolerance (±20%), core material (ferrite), shielding configuration (unshielded), and package dimensions (4.50mm x 4.00mm x 3.50mm). The substitute meets or exceeds all electrical specifications of the original part.

Q: What are the key differences between these two inductors?

A: The SDR0403-3R9ML has a higher current rating (1.98 A vs. 1.84 A), lower DC resistance (76 mOhm vs. 93.7 mOhm), and an extended operating temperature range (-40°C to 125°C vs. -40°C to 100°C). These differences represent performance improvements over the original specification.

Q: Are there any package or mounting differences?

A: No. Both inductors are surface mount components with identical physical dimensions and nonstandard package configurations. No PCB layout modifications are required for substitution.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the CD43NP-3R9MC and SDR0403-3R9ML are RoHS3 compliant with MSL 1 (Unlimited) moisture sensitivity ratings, ensuring compatibility with standard manufacturing and assembly processes.

Q: Which inductor has better thermal performance?

A: The SDR0403-3R9ML exhibits superior thermal performance due to its lower maximum DC resistance (76 mOhm vs. 93.7 mOhm), resulting in reduced resistive power dissipation under identical current conditions.

Q: Can the substitute part handle higher current applications?

A: The SDR0403-3R9ML is rated for 1.98 A continuous current, compared to 1.84 A for the CD43NP-3R9MC. This higher rating provides additional current capacity and design margin for applications approaching the original part's current limit.