PM40-180K Equivalent & Substitute Parts

Part Overview

The PM40-180K is a 18 µH unshielded molded inductor manufactured by Bourns Inc., rated for 190 mA with a maximum DC resistance of 2.8Ohm in a 1812 (4532 Metric) surface mount package. This part is classified as obsolete, making equivalent and substitute components necessary for ongoing design support and production continuity. Substitute parts must maintain electrical performance within the specified inductance, current rating, and DC resistance parameters while accommodating packaging and compliance requirements.

Key Parameters

Parameter	Value
Inductance	18 µH
Current Rating	190 mA
DC Resistance (DCR)	2.8Ohm Max
Package / Case	1812 (4532 Metric)
Mounting Type	Surface Mount
Operating Temperature Range	-55°C ~ 125°C
Shielding	Unshielded
Frequency - Self Resonant	15MHz

Substitute Part Grouping Explanation

Substitute parts for the PM40-180K are qualified based on the following electrical and mechanical parameters:

Primary Substitution Criteria:

Inductance: 18 µH (exact match required)
Current Rating: 190 mA minimum
DC Resistance: 2.8Ohm maximum
Package: 1812 (4532 Metric) surface mount
Shielding: Unshielded configuration
Self Resonant Frequency: 15MHz or higher

Direct Substitutes maintain all primary criteria with identical electrical specifications and active product status. Similar Substitutes meet the core electrical requirements but may have variations in core material, tolerance, or operating temperature range that require circuit-level verification.

Parameter Comparison

Part Number	Manufacturer	Inductance	Current Rating (mA)	DCR (Ohm Max)	Core Type	Tolerance	Operating Temp (°C)	Product Status	RoHS Status
PM40-180K	Bourns Inc.	18 µH	190	2.8	Iron Powder	±10%	-55 ~ 125	Obsolete	Non-compliant
CM453232-180JL	Bourns Inc.	18 µH	190	2.8	Ferrite	±5%	-40 ~ 125	Active	ROHS3 Compliant
CM453232-180KL	Bourns Inc.	18 µH	190	2.8	Ferrite	±10%	-40 ~ 125	Active	ROHS3 Compliant
1812-183J	API Delevan Inc.	18 µH	268	2.8	Ferrite	±5%	-55 ~ 125	Active	Non-compliant
744766118	Würth Elektronik	18 µH	190	2.8	Ferrite	±10%	-40 ~ 105	Active	ROHS3 Compliant
IMC1812ER180K	Vishay Dale	18 µH	190	2.8	Iron Powder	±10%	-55 ~ 125	Active	ROHS3 Compliant

Engineering Selection Recommendations

Preferred Direct Substitutes (Active Status, Full Compliance):

CM453232-180KL and CM453232-180JL from Bourns Inc. are the primary recommended substitutes. Both are active products with ROHS3 compliance. CM453232-180KL matches the PM40-180K tolerance specification (±10%) and operating temperature range (-40°C ~ 125°C minimum). CM453232-180JL offers tighter tolerance (±5%) for applications requiring improved inductance accuracy.

IMC1812ER180K from Vishay Dale provides an alternative with identical electrical specifications, iron powder core material matching the original design, and ROHS3 compliance. Operating temperature range extends to -55°C ~ 125°C, matching the original part.

744766118 from Würth Elektronik meets all electrical requirements with ROHS3 compliance and active product status. Operating temperature range is -40°C ~ 105°C, which is narrower than the original specification.

Alternative Substitute (Higher Current Rating):

1812-183J from API Delevan Inc. is an active product with 268 mA current rating, exceeding the 190 mA requirement. This part is suitable for applications where additional current margin is beneficial. Operating temperature range matches the original (-55°C ~ 125°C), but RoHS compliance is non-compliant.

Frequently Asked Questions (FAQ)

Q: Can CM453232-180KL directly replace PM40-180K in production?

A: Yes. CM453232-180KL meets all electrical specifications: 18 µH inductance, 190 mA current rating, 2.8Ohm maximum DCR, and 1812 package. The part is active with ROHS3 compliance. Operating temperature minimum is -40°C versus -55°C for the original; verify this meets your application requirements.

Q: What is the difference between CM453232-180JL and CM453232-180KL?

A: Both are Bourns CM45 series parts with identical electrical performance. CM453232-180JL has ±5% inductance tolerance versus ±10% for CM453232-180KL. Select CM453232-180JL for applications requiring tighter inductance accuracy.

Q: Why does 1812-183J have a higher current rating (268 mA) than the original?

A: 1812-183J is a different design from API Delevan with enhanced current handling capability while maintaining the same 18 µH inductance and 2.8Ohm DCR. This part is suitable as a substitute when additional current margin is required, though RoHS compliance differs from the original.

Q: Are there temperature range limitations when substituting?

A: Yes. The original PM40-180K operates from -55°C ~ 125°C. CM453232-180KL, CM453232-180JL, and 744766118 have minimum operating temperatures of -40°C. IMC1812ER180K and 1812-183J extend to -55°C. Verify your application's temperature requirements before selection.

Q: Is the core material change from iron powder to ferrite significant?

A: Core material affects frequency response, Q factor, and saturation characteristics. CM453232-180KL and CM453232-180JL use ferrite cores versus the iron powder core in PM40-180K. Both maintain the specified electrical parameters at the test frequency (2.52 MHz). Circuit-level validation is recommended for applications sensitive to core material differences.

Q: What is the packaging difference between these substitutes?

A: All substitutes use the 1812 (4532 Metric) surface mount package with identical footprint dimensions (0.177" L x 0.126" W / 4.50mm x 3.20mm). Height variations exist: PM40-180K is 0.126" (3.20mm), while most substitutes are 0.134" (3.40mm) or 0.142" (3.60mm). Verify PCB clearance for height-sensitive applications.

Q: Which substitute offers the best RoHS compliance?

A: CM453232-180KL, CM453232-180JL, 744766118, and IMC1812ER180K are all ROHS3 compliant. 1812-183J and the original PM40-180K are RoHS non-compliant. For new designs or RoHS-mandated applications, select from the ROHS3 compliant options.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message