PM40-3R3K Equivalent & Substitute Parts

Part Overview

The PM40-3R3K is a 3.3 µH unshielded molded inductor manufactured by Bourns Inc., rated for 355 mA with 800mOhm maximum DC resistance in a 1812 (4532 Metric) surface mount package. This component operates across -55°C to 125°C and is classified as obsolete. Due to its obsolete status, equivalent and substitute parts from active product lines are necessary for new designs and ongoing production requirements.

Substiute Parts

PM40-3R3K

Bourns Inc.In Stock: 1105PM40-3R3K Datasheet

Current PartRFQ

CM453232-3R3JL

Bourns Inc.In Stock: 1093CM453232-3R3JL Datasheet

DirectRFQ

CM453232-3R3KL

Bourns Inc.In Stock: 1620CM453232-3R3KL Datasheet

DirectRFQ

PM1812-3R3J-RC

Bourns Inc.In Stock: 1202PM1812-3R3J-RC Datasheet

SimilarRFQ

1812-332J

API Delevan Inc.In Stock: 6811812-332J Datasheet

SimilarRFQ

3613C3R3K

TE Connectivity Passive ProductIn Stock: 18393613C3R3K Datasheet

SimilarRFQ

74476603

Würth ElektronikIn Stock: 252474476603 Datasheet

SimilarRFQ

IMC1812RQ3R3K

Vishay DaleIn Stock: 848IMC1812RQ3R3K Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict alignment with the following electrical and mechanical parameters:

• Inductance Value: 3.3 µH (exact match required)
• Current Rating: Minimum 355 mA
• DC Resistance: 800mOhm maximum
• Package / Case: 1812 (4532 Metric) surface mount
• Shielding: Unshielded
• Q @ Frequency: 50 @ 7.96MHz or equivalent
• Self Resonant Frequency: 45MHz or higher
• Mounting Type: Surface Mount

Substitute parts are classified into two categories: Direct Substitutes (identical electrical and mechanical specifications) and Similar Substitutes (compatible within specified parameters but with variations in core material, tolerance, or temperature range).

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Bourns Inc. CM45 Series)

CM453232-3R3KL and CM453232-3R3JL are direct substitutes from Bourns Inc.'s active CM45 product line. Both maintain identical inductance, current rating, and DC resistance specifications. CM453232-3R3KL matches the ±10% tolerance of the original PM40-3R3K, while CM453232-3R3JL offers tighter ±5% tolerance. Both are ROHS3 compliant and support the full 125°C upper operating temperature. The lower temperature limit is -40°C versus the original -55°C.

Active Bourns Alternative (PM1812 Series)

PM1812-3R3J-RC is an active Bourns product with identical electrical specifications but operates to 100°C maximum, which is 25°C lower than the original. This part is ROHS3 compliant and suitable for applications not requiring the full -55°C to 125°C range.

Multi-Manufacturer Alternatives

1812-332J (API Delevan Inc.) provides higher current rating (501 mA versus 355 mA) with identical inductance and DCR, supporting the full -55°C to 125°C temperature range. RoHS non-compliance matches the original part status.

3613C3R3K (TE Connectivity) maintains all critical electrical parameters with ±10% tolerance and ROHS3 compliance but operates to 100°C maximum.

74476603 (Würth Elektronik) and IMC1812RQ3R3K (Vishay Dale) both meet all electrical specifications. IMC1812RQ3R3K uses iron powder core material matching the original and supports the full temperature range but is RoHS non-compliant.

Compliance Considerations

For RoHS3-compliant designs, select from CM453232-3R3KL, CM453232-3R3JL, PM1812-3R3J-RC, 3613C3R3K, or 74476603. For applications requiring full -55°C to 125°C operation with RoHS non-compliance acceptable, IMC1812RQ3R3K or 1812-332J are suitable.

Frequently Asked Questions (FAQ)

Q: Can CM453232-3R3KL directly replace PM40-3R3K in all applications?

A: CM453232-3R3KL meets all critical electrical parameters (3.3 µH, 355 mA, 800mOhm DCR) and package specifications. The primary difference is the lower minimum operating temperature (-40°C versus -55°C). Verify your application's temperature requirements before substitution.

Q: What is the difference between CM453232-3R3KL and CM453232-3R3JL?

A: Both are electrically equivalent with identical inductance, current rating, and DCR. CM453232-3R3JL offers tighter tolerance (±5% versus ±10%), which may be beneficial for precision applications. Both are ROHS3 compliant and support -40°C to 125°C operation.

Q: Why does 1812-332J have a higher current rating (501 mA) than the original?

A: 1812-332J is rated for higher current capacity while maintaining the same inductance and DCR specifications. This part is compatible with PM40-3R3K applications and provides additional current margin.

Q: Are all substitute parts available in the same package?

A: All listed substitutes use the 1812 (4532 Metric) surface mount package. Physical dimensions are consistent across all parts, ensuring PCB layout compatibility.

Q: Which substitute offers the best RoHS compliance?

A: CM453232-3R3KL, CM453232-3R3JL, PM1812-3R3J-RC, 3613C3R3K, and 74476603 are all ROHS3 compliant. IMC1812RQ3R3K and 1812-332J maintain RoHS non-compliance status matching the original PM40-3R3K.

Q: Can I use these substitutes in high-temperature applications?

A: Most substitutes support operation to 100°C or 105°C maximum. Only CM453232-3R3KL, CM453232-3R3JL, 1812-332J, and IMC1812RQ3R3K support the full 125°C upper limit. Verify your application's maximum operating temperature requirement.

Q: What core material differences exist among the substitutes?

A: PM40-3R3K uses iron powder core. Substitutes employ either ferrite or iron powder cores. Ferrite-core parts (CM453232 series, PM1812, 3613C3R3K, 74476603) and iron powder-core parts (IMC1812RQ3R3K) are electrically equivalent within specified parameters. Core material selection depends on application-specific requirements such as frequency response or EMI characteristics.