PM20-3R3K Equivalent & Substitute Parts

Part Overview

The PM20-3R3K is a 3.3 µH unshielded molded inductor manufactured by Bourns Inc., rated for 260 mA with a maximum DC resistance of 1.2Ohm. This component operates across the temperature range of -55°C to 125°C in a 1210 (3225 Metric) surface mount package. The part is currently obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements.

Substiute Parts

PM20-3R3K

Bourns Inc.In Stock: 973PM20-3R3K Datasheet

Current PartRFQ

CM322522-3R3JL

Bourns Inc.In Stock: 10718CM322522-3R3JL Datasheet

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CM322522-3R3KL

Bourns Inc.In Stock: 4795CM322522-3R3KL Datasheet

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1210-332J

API Delevan Inc.In Stock: 12791210-332J Datasheet

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74476403

Würth ElektronikIn Stock: 330774476403 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PM20-3R3K is determined by the following critical parameters:

• Inductance Value: Must be 3.3 µH (exact match required)
• DC Resistance: Must not exceed 1.2Ohm maximum
• Core Material: Ferrite (unshielded)
• Package / Case: 1210 (3225 Metric) surface mount form factor
• Physical Dimensions: 0.126" L x 0.098" W (3.20mm x 2.50mm) with height ≤ 0.087" (2.20mm)

Substitute parts are grouped into two categories based on current rating capability:

Category A - Full Current Rating Match (260 mA):

• 74476403 (Würth Elektronik WE-GF series)

Category B - Reduced Current Rating (180 mA):

• CM322522-3R3JL (Bourns Inc.)
• CM322522-3R3KL (Bourns Inc.)

Category C - Elevated Current Rating (393 mA):

• 1210-332J (API Delevan Inc.)

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred): The 74476403 (Würth Elektronik WE-GF series) provides the closest electrical match with identical current rating (260 mA), DC resistance (1.2Ohm max), and inductance (3.3 µH). This part is active in production and ROHS3 compliant. Physical dimensions are equivalent. The operating temperature range is reduced to -40°C ~ 105°C; verify compatibility with your application's thermal requirements.

For RoHS3 Compliance Requirement: Both CM322522-3R3JL and CM322522-3R3KL meet ROHS3 compliance standards and maintain the full operating temperature range (-40°C ~ 125°C). These parts feature drum core, wirewound construction with tighter tolerance (±5% for CM322522-3R3JL). Current rating is reduced to 180 mA; select only if your circuit operates below this threshold. Package designation is nonstandard; physical dimensions remain compatible.

For Elevated Current Applications: The 1210-332J (API Delevan Inc.) supports 393 mA current rating, exceeding the original specification. This part maintains the 1210 package form factor and full temperature range (-55°C ~ 125°C). Height is increased to 0.101" (2.57mm); verify PCB layout clearance. RoHS compliance status is non-compliant.

For Legacy Non-Compliant Designs: The 1210-332J maintains RoHS non-compliant status matching the original PM20-3R3K, suitable for applications where compliance is not required.

Frequently Asked Questions (FAQ)

Q: Can CM322522-3R3JL and CM322522-3R3KL be used interchangeably with PM20-3R3K? A: Both parts share identical inductance (3.3 µH), DC resistance (1.2Ohm max), and physical dimensions. The primary difference is reduced current rating (180 mA vs. 260 mA). Selection depends on circuit current requirements. CM322522-3R3JL offers tighter tolerance (±5%) compared to the original ±10%.

Q: What is the impact of the nonstandard package designation for CM322522 series? A: Despite the nonstandard package label, physical dimensions (0.126" L x 0.098" W, 3.20mm x 2.50mm) and height (0.087" max) are compatible with 1210 footprints. Verify with your PCB design tool that the nonstandard designation does not conflict with your component library.

Q: Is 74476403 suitable for all PM20-3R3K applications? A: The 74476403 matches current rating and electrical specifications. Operating temperature range is reduced to -40°C ~ 105°C. Verify your application does not require operation below -40°C or above 105°C. MSL rating is 3 (168 Hours); confirm moisture handling procedures align with your manufacturing process.

Q: Why does 1210-332J have a higher current rating? A: The 1210-332J is rated for 393 mA, exceeding the original 260 mA specification. This part can be used in applications requiring the original current rating without derating. Height is increased to 0.101" (2.57mm); confirm PCB layout accommodates this dimension.

Q: Which substitute offers the best compliance profile? A: Both 74476403 and CM322522 series (CM322522-3R3JL, CM322522-3R3KL) are ROHS3 compliant. The CM322522 series maintains MSL 1 (Unlimited) rating, while 74476403 requires MSL 3 handling (168 Hours). For compliance-critical applications, CM322522 series is preferred.

Q: Are there temperature range limitations I should consider? A: The original PM20-3R3K operates -55°C ~ 125°C. Substitute 74476403 is limited to -40°C ~ 105°C. CM322522 series and 1210-332J support -40°C ~ 125°C and -55°C ~ 125°C respectively. Select based on your application's minimum and maximum operating temperatures.