PM20-R18M Equivalent & Substitute Parts

Part Overview

The PM20-R18M is a 180 nH unshielded molded inductor manufactured by Bourns Inc., rated for 450 mA with a maximum DC resistance of 280 mOhm. This component operates across a temperature range of -55°C to 125°C in a 1210 (3225 Metric) surface mount package. The part is currently obsolete, necessitating identification of functionally equivalent alternatives from active product lines to maintain design continuity and ensure supply chain availability.

Substiute Parts

PM20-R18M

Bourns Inc.In Stock: 1042PM20-R18M Datasheet

Current PartRFQ

CM453232-120KL

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

DirectRFQ

CM322522-R18ML

Bourns Inc.In Stock: 905CM322522-R18ML Datasheet

SimilarRFQ

1210-181K

API Delevan Inc.In Stock: 10351210-181K Datasheet

SimilarRFQ

AISM-1210-R18M-T

Abracon LLCIn Stock: 1048AISM-1210-R18M-T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PM20-R18M is determined by the following critical parameters: inductance value (180 nH), tolerance (±20%), current rating (minimum 450 mA), DC resistance (280 mOhm maximum), package type (1210 / 3225 Metric), and unshielded configuration. Substitute parts must maintain electrical performance within these specifications and support surface mount assembly.

The substitute parts are grouped into two categories:

Direct Electrical Equivalents: Parts matching the 180 nH inductance, 450 mA current rating, and 280 mOhm DC resistance specifications with identical or superior performance characteristics.

Functional Alternatives: Parts with matching inductance and package dimensions but with variations in current rating, DC resistance, or core material that may be suitable depending on circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

AISM-1210-R18M-T (Abracon LLC) provides the closest electrical and mechanical match to the PM20-R18M. This part maintains identical inductance (180 nH), current rating (450 mA), DC resistance (280 mOhm), and package dimensions (1210 / 3225 Metric). The component is ROHS3 compliant and currently in active production. The operating temperature range is -40°C to 85°C, which is narrower than the original part; applications requiring operation below -40°C or above 85°C require thermal analysis.

1210-181K (API Delevan Inc.) matches the PM20-R18M in inductance, DC resistance, and package type with a higher current rating (860 mA). This part supports the full temperature range (-55°C to 125°C) matching the original specification. The iron core material differs from the ferrite core of the original part. This substitute is suitable for applications where the higher current capacity and extended temperature range provide design margin.

CM322522-R18ML (Bourns Inc.) maintains the 180 nH inductance and ferrite core material but exhibits higher DC resistance (810 mOhm maximum) and lower current rating (220 mA). This part is ROHS3 compliant and operates across -40°C to 125°C. The nonstandard package designation and elevated DC resistance make this option suitable only for low-current applications where the original 450 mA rating is not required.

CM453232-120KL (Bourns Inc.) differs significantly in inductance value (12 µH versus 180 nH) and is not electrically equivalent to the PM20-R18M. This part is not recommended as a substitute.

Frequently Asked Questions (FAQ)

Q: Can AISM-1210-R18M-T replace PM20-R18M in all applications?

A: AISM-1210-R18M-T provides electrical equivalence with matching inductance, current rating, and DC resistance. The operating temperature range is -40°C to 85°C compared to the original -55°C to 125°C. Verify that your application does not require operation outside this narrower temperature window.

Q: What is the difference between the iron core (1210-181K) and ferrite core (PM20-R18M) options?

A: Both materials provide the required inductance and DC resistance specifications. Iron core inductors typically exhibit different frequency response and Q factor characteristics. The 1210-181K offers higher current capacity (860 mA) and extended temperature range (-55°C to 125°C). Select based on frequency response requirements and thermal operating conditions.

Q: Why does CM322522-R18ML have higher DC resistance than the original part?

A: CM322522-R18ML uses a drum core wirewound construction, which results in higher DC resistance (810 mOhm) compared to the molded construction of PM20-R18M (280 mOhm). This part is suitable only for applications where the 220 mA current rating is sufficient and DC resistance elevation does not impact circuit performance.

Q: Are all substitute parts RoHS compliant?

A: AISM-1210-R18M-T and CM322522-R18ML are ROHS3 compliant. The 1210-181K and original PM20-R18M are RoHS non-compliant. Verify compliance requirements for your application and supply chain.

Q: Do all substitute parts use the same 1210 package?

A: AISM-1210-R18M-T and 1210-181K use standard 1210 (3225 Metric) packages with identical footprints. CM322522-R18ML uses a nonstandard package with the same physical dimensions (0.126" L x 0.098" W) but may require design verification for PCB layout compatibility.