PM40-8R2K Equivalent & Substitute Parts

Part Overview

The PM40-8R2K is an 8.2 µH unshielded molded inductor manufactured by Bourns Inc., rated for 270 mA with a maximum DC resistance of 1.4Ohm in a 1812 (4532 Metric) surface mount package. This part is classified as obsolete, making equivalent and substitute components necessary for new designs and ongoing production requirements. Substitute parts maintain the core electrical specifications while offering improved availability and compliance status.

Key Parameters

Parameter	Value
Inductance	8.2 µH
Current Rating	270 mA
DC Resistance (Max)	1.4Ohm
Package / Case	1812 (4532 Metric)
Shielding	Unshielded
Mounting Type	Surface Mount
Operating Temperature Range	-55°C ~ 125°C
Inductance Tolerance	±10%
Q @ Frequency	50 @ 7.96MHz
Self Resonant Frequency	25MHz

Substitute Part Grouping Explanation

Substitute parts are classified based on electrical and mechanical compatibility with the PM40-8R2K. The primary substitution criteria are:

Critical Parameters (Must Match):

Inductance: 8.2 µH
Current Rating: 270 mA minimum
DC Resistance: 1.4Ohm maximum
Package: 1812 (4532 Metric)
Shielding: Unshielded
Mounting Type: Surface Mount

Direct Substitutes maintain all critical parameters with identical or tighter tolerances and active product status:

CM453232-8R2JL (Bourns Inc., ±5% tolerance, ferrite core, active)
CM453232-8R2KL (Bourns Inc., ±10% tolerance, ferrite core, active)
IMC1812ER8R2K (Vishay Dale, ±10% tolerance, iron powder core, active)

Similar Substitutes meet all critical electrical parameters but may have minor variations in operating temperature range, core material, or height:

1812-822J (API Delevan Inc., 375 mA rating, ferrite core, active)
3613C8R2K (TE Connectivity, ferrite core, active)
744766082 (Würth Elektronik, ferrite core, active)

Parameter Comparison

Part Number	Manufacturer	Inductance	Current Rating (mA)	DCR (Ohm Max)	Tolerance	Core Material	Operating Temp (°C)	Product Status	RoHS Status
PM40-8R2K	Bourns Inc.	8.2 µH	270	1.4	±10%	Iron Powder	-55 ~ 125	Obsolete	Non-compliant
CM453232-8R2JL	Bourns Inc.	8.2 µH	270	1.4	±5%	Ferrite	-40 ~ 125	Active	ROHS3 Compliant
CM453232-8R2KL	Bourns Inc.	8.2 µH	270	1.4	±10%	Ferrite	-40 ~ 125	Active	ROHS3 Compliant
IMC1812ER8R2K	Vishay Dale	8.2 µH	270	1.4	±10%	Iron Powder	-55 ~ 125	Active	ROHS3 Compliant
1812-822J	API Delevan Inc.	8.2 µH	375	1.4	±5%	Ferrite	-55 ~ 125	Active	Non-compliant
3613C8R2K	TE Connectivity	8.2 µH	270	1.4	±10%	Ferrite	-30 ~ 100	Active	ROHS3 Compliant
744766082	Würth Elektronik	8.2 µH	270	1.4	±10%	Ferrite	-40 ~ 105	Active	ROHS3 Compliant

Engineering Selection Recommendations

For RoHS3 Compliance Requirements: CM453232-8R2KL, CM453232-8R2JL, IMC1812ER8R2K, 3613C8R2K, and 744766082 are all ROHS3 compliant. The PM40-8R2K and 1812-822J are non-compliant and unsuitable for applications requiring RoHS certification.

For Extended Temperature Range (-55°C to 125°C): IMC1812ER8R2K and 1812-822J maintain the full temperature range of the original PM40-8R2K. CM453232 variants and 744766082 operate to -40°C minimum, while 3613C8R2K is limited to -30°C minimum.

For Active Product Status: All substitute parts listed are active products except PM40-8R2K, which is obsolete. Active status ensures ongoing availability and manufacturer support.

For Tolerance Matching: CM453232-8R2JL offers ±5% tolerance for applications requiring tighter inductance control. All other substitutes maintain ±10% tolerance matching the original specification.

For Core Material Consistency: IMC1812ER8R2K uses iron powder core material identical to PM40-8R2K. Ferrite core alternatives (CM453232 series, 3613C8R2K, 744766082, 1812-822J) provide equivalent electrical performance within specified tolerances.

Frequently Asked Questions (FAQ)

Q: Can CM453232-8R2KL directly replace PM40-8R2K in all applications? A: Yes, CM453232-8R2KL meets all critical electrical parameters (8.2 µH, 270 mA, 1.4Ohm DCR) and package specifications. The primary difference is the operating temperature minimum of -40°C versus -55°C for the original part. Applications operating above -40°C will experience no functional difference.

Q: What is the difference between CM453232-8R2JL and CM453232-8R2KL? A: Both parts are electrically equivalent with identical inductance, current rating, and DC resistance. CM453232-8R2JL offers ±5% inductance tolerance compared to ±10% for CM453232-8R2KL. Selection depends on tolerance requirements for the specific application.

Q: Why does 1812-822J have a higher current rating (375 mA) than the original PM40-8R2K (270 mA)? A: The 1812-822J is rated for higher current capacity while maintaining the same inductance and DC resistance specifications. This part is suitable for applications requiring the PM40-8R2K specifications and can handle higher current loads without saturation.

Q: Are all substitute parts available in the same packaging format? A: All substitute parts 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 range from 0.126" to 0.142" (3.20mm to 3.60mm), which may require PCB layout verification for applications with height constraints.

Q: Which substitute part is recommended for new designs? A: CM453232-8R2KL is recommended for new designs due to active product status, ROHS3 compliance, and availability from the original manufacturer (Bourns Inc.). IMC1812ER8R2K is an alternative if iron powder core material is required for specific circuit performance characteristics.

Q: What is the moisture sensitivity level for these parts? A: All parts listed, including PM40-8R2K and all substitutes, have MSL 1 (Unlimited) rating, indicating no moisture sensitivity concerns for storage and handling.

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