SD3812-820-R Equivalent & Substitute Parts

Part Overview

The SD3812-820-R is a 82 µH shielded drum core wirewound inductor manufactured by Eaton - Electronics Division. This surface mount component is rated for 259 mA continuous current with a DC resistance of 2.885 Ohm and operates across the temperature range of -40°C to 85°C. The part is classified as obsolete, making identification of suitable substitute components essential for ongoing design support and production continuity. The nonstandard package configuration and specific electrical characteristics require careful parameter matching when selecting alternative inductors.

Substiute Parts

SD3812-820-R

Eaton - Electronics DivisionIn Stock: 882SD3812-820-R Datasheet

Current PartRFQ

CDRH3D28/LDNP-820NC

Sumida America Components Inc.In Stock: 879CDRH3D28/LDNP-820NC Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SD3812-820-R is based on the following critical electrical and mechanical parameters:

Primary Matching Criteria:

• Inductance value: 82 µH (tolerance range acceptable within design margins)
• Shielding requirement: Shielded configuration
• Core material: Ferrite
• Mounting type: Surface Mount
• Inductance test frequency: 100 kHz

Secondary Compatibility Factors:

• Current rating must meet or exceed the application requirement of 259 mA
• DC resistance must be compatible with circuit design specifications
• Operating temperature range must encompass the application environment
• Saturation current characteristics must support circuit performance
• Moisture sensitivity level and compliance certifications

The CDRH3D28/LDNP-820NC from Sumida America Components Inc. satisfies the primary matching criteria with equivalent inductance value, shielded ferrite core construction, and surface mount configuration. This substitute maintains the same inductance test frequency and core material specifications.

Parameter Comparison

Engineering Selection Recommendations

The CDRH3D28/LDNP-820NC is a suitable substitute for the obsolete SD3812-820-R based on the following engineering factors:

Electrical Compatibility: The substitute maintains the identical 82 µH inductance value at 100 kHz test frequency with ferrite core construction. The higher current rating of 580 mA provides design margin above the original 259 mA specification. The significantly lower DC resistance of 540 mOhm (versus 2.885 Ohm) reduces power dissipation in the circuit.

Thermal Performance: The extended operating temperature range of -40°C to 105°C encompasses the original -40°C to 85°C specification, providing additional thermal margin for applications requiring higher temperature operation.

Product Availability and Compliance: The substitute is classified as Active product status with current manufacturing support, addressing the obsolescence issue of the original part. ROHS3 compliance certification ensures compatibility with current environmental and regulatory requirements.

Packaging and Handling: Both components feature identical moisture sensitivity level (MSL 1 - Unlimited), eliminating special storage or handling requirements during transition.

Design Verification Requirement: The wider inductance tolerance of ±30% (versus ±15%) and lower saturation current of 172 mA (versus 276 mA) require circuit-level validation to confirm performance within application specifications.

Frequently Asked Questions (FAQ)

Q: Can the CDRH3D28/LDNP-820NC directly replace the SD3812-820-R without circuit modification?

A: Direct replacement is possible for applications where the lower saturation current of 172 mA and wider inductance tolerance of ±30% are acceptable. Circuit validation is required to confirm performance margins, particularly in current-limited or resonant circuit applications.

Q: What is the impact of the lower DC resistance in the substitute part?

A: The substitute's DC resistance of 540 mOhm (versus 2.885 Ohm) results in significantly lower power dissipation and reduced thermal generation. This is generally beneficial for circuit efficiency but may require recalculation of voltage drops and thermal management in the application circuit.

Q: Are there physical package compatibility concerns?

A: The substitute has slightly different dimensions: 0.150" L x 0.150" W x 0.118" H (3.80mm x 3.80mm x 3.00mm) compared to the original 0.157" L x 0.157" W x 0.047" H (4.00mm x 4.00mm x 1.20mm). PCB layout verification is necessary to confirm mechanical fit within the available space.

Q: Does the substitute meet current environmental compliance standards?

A: Yes. The CDRH3D28/LDNP-820NC carries ROHS3 compliance certification, meeting current environmental and regulatory requirements for electronic components in most jurisdictions.

Q: What is the significance of the different saturation current specifications?

A: The substitute's lower saturation current of 172 mA (versus 276 mA) indicates the inductor will saturate at a lower current level. Applications operating near the original saturation point require verification that the substitute's saturation characteristics do not degrade circuit performance.

Q: Is the extended temperature range of the substitute beneficial?

A: The substitute's -40°C to 105°C operating range provides additional thermal margin beyond the original -40°C to 85°C specification. This is advantageous for applications in elevated temperature environments or those requiring extended thermal safety margins.