PM3308-331M Equivalent & Substitute Parts

Part Overview

The PM3308-331M is a 330 µH unshielded drum core wirewound inductor manufactured by Bourns Inc., rated for 300 mA continuous current with a maximum DC resistance of 2.7Ohm. This surface mount component operates across -55°C to 125°C and is currently classified as obsolete. Due to its discontinued status, identifying functionally equivalent alternatives is essential for design continuity and procurement planning.

Substiute Parts

PM3308-331M

Bourns Inc.In Stock: 1003PM3308-331M Datasheet

Current PartRFQ

P0762.334NLT

Pulse ElectronicsIn Stock: 884P0762.334NLT Datasheet

DirectRFQ

AX97-20331

Triad MagneticsIn Stock: 761AX97-20331 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PM3308-331M is determined by the following critical parameters:

• Inductance value: 330 µH ±20%
• Current rating: minimum 300 mA continuous
• DC resistance: maximum 2.7Ohm
• Saturation current: minimum 400 mA
• Shielding configuration: unshielded
• Mounting type: surface mount
• Test frequency: 100 kHz
• Physical footprint compatibility: nonstandard package with maximum dimensions 0.512" L x 0.374" W x 0.118" H

Two substitute parts meet these electrical and mechanical criteria:

Direct Substitute: P0762.334NLT (Pulse Electronics) — matches all electrical specifications with identical inductance, current rating, DCR, and saturation current. Dimensions are within tolerance (0.510" L x 0.370" W x 0.118" H).

Similar Substitute: AX97-20331 (Triad Magnetics) — meets inductance, current rating, and core type requirements. DCR is 2Ohm Max (lower than 2.7Ohm specification), and dimensions are slightly larger (0.530" L x 0.370" W x 0.138" H).

Parameter Comparison

Engineering Selection Recommendations

P0762.334NLT (Pulse Electronics) is the primary substitute for PM3308-331M. This part maintains electrical equivalence across all specified parameters and achieves dimensional compatibility within tolerance. The part is currently in active production status, ensuring long-term availability. P0762.334NLT carries ROHS3 compliance, providing regulatory advantage over the original obsolete component.

AX97-20331 (Triad Magnetics) serves as a secondary alternative when P0762.334NLT is unavailable. This part satisfies the core electrical requirements (330 µH inductance, 300 mA rating, ferrite drum core construction) and is actively manufactured. The lower DCR specification (2Ohm Max versus 2.7Ohm Max) represents an improvement in power efficiency. However, the operating temperature range (-40°C ~ 85°C) is narrower than the original specification, and physical dimensions are slightly larger (0.138" height versus 0.118" height), requiring PCB layout verification. AX97-20331 also carries ROHS3 compliance.

Both substitutes are available in active production with established supply chains, addressing the procurement challenges posed by the PM3308-331M obsolescence.

Frequently Asked Questions (FAQ)

Q: Can P0762.334NLT directly replace PM3308-331M without circuit modification?

A: Yes. P0762.334NLT matches all critical electrical parameters: 330 µH inductance, 300 mA current rating, 2.7Ohm maximum DCR, and 400 mA saturation current. Physical dimensions are within tolerance (0.510" L x 0.370" W versus 0.512" L x 0.374" W), permitting direct PCB substitution.

Q: What are the limitations of using AX97-20331 as a substitute?

A: AX97-20331 meets electrical specifications but has three considerations: (1) operating temperature range is -40°C ~ 85°C, which does not extend to the original -55°C lower limit; (2) physical height is 0.138" versus 0.118", requiring clearance verification on the PCB; (3) saturation current is not specified in available documentation.

Q: Does the lower DCR of AX97-20331 (2Ohm Max) affect circuit performance?

A: Lower DCR reduces resistive losses and heat generation, which is beneficial for power efficiency. However, if the circuit design relies on the specific impedance characteristics of the 2.7Ohm specification, this difference must be evaluated in the application context.

Q: Are there temperature range implications when substituting?

A: PM3308-331M operates -55°C ~ 125°C. P0762.334NLT covers -40°C ~ 130°C, providing adequate range for most applications. AX97-20331 operates -40°C ~ 85°C, which does not meet the original lower temperature specification. Application requirements must be assessed accordingly.

Q: What is the impact of RoHS compliance differences?

A: PM3308-331M is RoHS non-compliant. Both P0762.334NLT and AX97-20331 are ROHS3 compliant, meeting current regulatory requirements for new designs and procurement in regulated markets.

Q: Are physical dimension differences critical for PCB layout?

A: P0762.334NLT dimensions (0.510" L x 0.370" W x 0.118" H) are within tolerance of the original. AX97-20331 is slightly larger (0.530" L x 0.370" W x 0.138" H). PCB footprint and clearance must be verified, particularly for height-constrained applications.