PM40-680K Equivalent & Substitute Parts

Part Overview

The PM40-680K is a 68 µH unshielded molded inductor manufactured by Bourns Inc., rated for 130 mA with a maximum DC resistance of 6Ohm 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 maintain the core electrical specifications while offering improved availability and compliance status.

Substiute Parts

PM40-680K

Bourns Inc.In Stock: 1057PM40-680K Datasheet

Current PartRFQ

CM453232-680JL

Bourns Inc.In Stock: 4213CM453232-680JL Datasheet

DirectRFQ

CM453232-680KL

Bourns Inc.In Stock: 14183CM453232-680KL Datasheet

DirectRFQ

1812-683J

API Delevan Inc.In Stock: 8321812-683J Datasheet

SimilarRFQ

744766168

Würth ElektronikIn Stock: 1875744766168 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PM40-680K are classified into two categories based on electrical and mechanical compatibility:

Direct Substitutes (Functionally Equivalent): CM453232-680JL and CM453232-680KL maintain identical inductance (68 µH), current rating (130 mA), DC resistance (6Ohm Max), package dimensions (1812/4532 Metric), and Q factor specifications. Both are active products with improved RoHS compliance. The primary difference is inductance tolerance: CM453232-680JL offers ±5% tolerance versus the PM40-680K's ±10%, while CM453232-680KL matches the ±10% tolerance. Operating temperature ranges differ slightly (-40°C to 125°C versus -55°C to 125°C).

Similar Substitutes (Electrical Compatibility with Parameter Variations): 1812-683J (API Delevan Inc.) and 744766168 (Würth Elektronik) maintain the same inductance, DC resistance, package, and Q factor. However, 1812-683J has a higher current rating (183 mA versus 130 mA) and operates across -55°C to 125°C. The 744766168 operates at a reduced temperature range (-40°C to 105°C) and has a slightly higher self-resonant frequency (10MHz versus 9MHz).

Parameter Comparison

Engineering Selection Recommendations

For applications requiring direct replacement of the PM40-680K with minimal design impact, CM453232-680KL is the primary recommendation. It maintains identical electrical specifications, operates within the same temperature range as the original part, and is ROHS3 compliant with active product status and high inventory availability (14,108 pcs).

CM453232-680JL offers improved inductance tolerance (±5% versus ±10%) and is suitable for applications where tighter tolerance specifications are beneficial, though it operates at a reduced lower temperature limit (-40°C versus -55°C).

1812-683J is suitable for applications where higher current headroom is required (183 mA versus 130 mA) and full temperature range operation (-55°C to 125°C) is necessary. However, this part does not meet RoHS3 compliance.

744766168 provides ROHS3 compliance and active product status but operates at a reduced upper temperature limit (105°C versus 125°C) and has a slightly elevated self-resonant frequency (10MHz versus 9MHz). This part is appropriate for applications operating within the -40°C to 105°C range.

Frequently Asked Questions (FAQ)

Q: Can CM453232-680JL and CM453232-680KL be used interchangeably with the PM40-680K?

A: Both Bourns CM45 series parts are direct substitutes. The primary difference is inductance tolerance: CM453232-680JL provides ±5% tolerance while CM453232-680KL matches the original ±10% tolerance. Both maintain identical current rating, DC resistance, package dimensions, and Q factor. Operating temperature range is -40°C to 125°C for both, compared to -55°C to 125°C for the PM40-680K.

Q: What is the difference between the Bourns CM45 series and the API Delevan 1812-683J?

A: The 1812-683J has a higher current rating (183 mA versus 130 mA) and maintains the full temperature range (-55°C to 125°C). All other electrical parameters—inductance, DC resistance, Q factor, and package—are identical. The 1812-683J does not meet RoHS3 compliance.

Q: Is the Würth Elektronik 744766168 suitable for all applications using the PM40-680K?

A: The 744766168 is suitable for applications operating within -40°C to 105°C. It is not recommended for applications requiring the full -55°C to 125°C temperature range or those operating above 105°C. The self-resonant frequency is slightly higher (10MHz versus 9MHz), which may affect performance in high-frequency applications near the resonant point.

Q: Are all substitute parts available in the same packaging format?

A: All substitute parts are supplied in 1812 (4532 Metric) surface mount packages with identical footprint dimensions (0.177" L x 0.126" W / 4.50mm x 3.20mm). Height variations exist: PM40-680K and CM45 series are 0.126" to 0.134" (3.20mm to 3.40mm), while 1812-683J and 744766168 are 0.134" to 0.142" (3.40mm to 3.60mm). Verify PCB clearance for applications with height constraints.

Q: Which substitute offers the best compliance profile?

A: CM453232-680KL and 744766168 both meet ROHS3 compliance with active product status. CM453232-680KL is recommended for applications requiring the full -55°C to 125°C temperature range, while 744766168 is suitable for -40°C to 105°C applications.