PM40-120K Equivalent & Substitute Parts

Part Overview

The PM40-120K is a 12 µH unshielded molded inductor manufactured by Bourns Inc., rated for 225 mA with a maximum DC resistance of 2Ohm. This component is designed for surface mount applications in the 1812 (4532 Metric) package format. The PM40-120K is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and procurement continuity.

Substiute Parts

PM40-120K

Bourns Inc.In Stock: 1072PM40-120K Datasheet

Current PartRFQ

CM453232-120JL

Bourns Inc.In Stock: 856CM453232-120JL Datasheet

DirectRFQ

CM453232-120KL

Bourns Inc.In Stock: 3108CM453232-120KL Datasheet

DirectRFQ

CM453232-5R6KL

Bourns Inc.In Stock: 4408CM453232-5R6KL Datasheet

DirectRFQ

PM1812-120J-RC

Bourns Inc.In Stock: 3241PM1812-120J-RC Datasheet

SimilarRFQ

1812-123J

API Delevan Inc.In Stock: 26631812-123J Datasheet

SimilarRFQ

IMC1812ER120K

Vishay DaleIn Stock: 750IMC1812ER120K Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PM40-120K are grouped based on strict electrical and mechanical compatibility criteria. The primary substitution parameters are:

• Inductance Value: 12 µH (exact match required for direct substitution)
• Current Rating: 225 mA minimum
• DC Resistance: 2Ohm maximum
• Package / Case: 1812 (4532 Metric) surface mount
• Frequency Characteristics: Q @ 2.52MHz and self-resonant frequency alignment

Direct Substitutes (CM453232-120JL, CM453232-120KL) maintain identical electrical specifications with active product status and improved compliance ratings. These parts are manufactured by Bourns Inc. using ferrite core construction with drum core, wirewound design.

Similar Substitutes (PM1812-120J-RC, 1812-123J, IMC1812ER120K) meet the core electrical requirements but may have minor variations in tolerance, temperature range, or core material composition. These parts are suitable for applications where the PM40-120K specifications are met.

Non-Direct Substitute (CM453232-5R6KL) differs in inductance value (5.6 µH) and current rating (300 mA) and is listed for reference only; it does not qualify as a direct substitute.

Parameter Comparison

Engineering Selection Recommendations

Preferred Direct Substitutes: CM453232-120JL and CM453232-120KL are the primary alternatives to the obsolete PM40-120K. Both parts are manufactured by Bourns Inc., maintain identical electrical specifications, and carry active product status with ROHS3 compliance. CM453232-120KL offers higher inventory availability (3012 Pcs) compared to CM453232-120JL (802 Pcs). The tolerance difference (±5% vs ±10%) in CM453232-120JL provides improved precision for applications requiring tighter inductance control.

Secondary Alternatives: PM1812-120J-RC (Bourns Inc.) and IMC1812ER120K (Vishay Dale) meet all core electrical requirements and carry active product status. PM1812-120J-RC is ROHS3 compliant but operates within a reduced temperature range (-40°C ~ 100°C) compared to the original specification. IMC1812ER120K maintains the full temperature range (-55°C ~ 125°C) and is ROHS3 compliant, offering compatibility with the original operating environment.

Cross-Manufacturer Option: The 1812-123J from API Delevan Inc. provides a higher current rating (317 mA) and maintains the full temperature range. However, this part carries RoHS non-compliant status, which may restrict use in regulated applications.

Frequently Asked Questions (FAQ)

Q: Can CM453232-120JL and CM453232-120KL be used interchangeably with PM40-120K?

A: Yes. Both parts maintain the same inductance (12 µH), current rating (225 mA), DC resistance (2Ohm Max), and package format (1812). The primary difference is tolerance specification (±5% vs ±10%) and core material composition (ferrite drum core vs molded iron powder). Both are electrically compatible for the PM40-120K application.

Q: What is the impact of the tolerance difference between PM40-120K (±10%) and CM453232-120JL (±5%)?

A: The ±5% tolerance in CM453232-120JL provides tighter inductance control, resulting in improved circuit performance consistency. Applications sensitive to inductance variation benefit from this specification. For general-purpose applications, both tolerance levels are functionally equivalent.

Q: Why is PM1812-120J-RC listed as a similar substitute rather than a direct substitute?

A: PM1812-120J-RC operates within a reduced temperature range (-40°C ~ 100°C) compared to the PM40-120K specification (-55°C ~ 125°C). Applications requiring full temperature range operation should use CM453232-120JL, CM453232-120KL, or IMC1812ER120K instead.

Q: Is the 1812-123J from API Delevan Inc. a suitable replacement?

A: The 1812-123J meets the core electrical requirements with a higher current rating (317 mA). However, it carries RoHS non-compliant status, which may conflict with regulatory requirements in certain applications. Use this part only when RoHS compliance is not mandated.

Q: What is the significance of core material differences (molded iron powder vs ferrite drum core)?

A: Core material affects frequency response, Q factor, and thermal characteristics. The PM40-120K uses molded iron powder construction, while CM453232 series uses ferrite drum core construction. Both achieve the specified Q @ 2.52MHz (50) and self-resonant frequency (18MHz), confirming electrical equivalence for the specified operating frequency.

Q: Can CM453232-5R6KL be used as a substitute?

A: No. CM453232-5R6KL has a different inductance value (5.6 µH) and higher current rating (300 mA), making it unsuitable as a direct substitute. This part is listed for reference only and should not be used in applications requiring 12 µH inductance.

Q: Which substitute offers the best compliance profile?

A: CM453232-120JL, CM453232-120KL, PM1812-120J-RC, and IMC1812ER120K all carry ROHS3 compliance. For applications requiring both ROHS3 compliance and full temperature range operation (-55°C ~ 125°C), CM453232-120KL and IMC1812ER120K are optimal selections.