PM43-4R7M Equivalent & Substitute Parts

Part Overview

The PM43-4R7M is a 4.7 µH unshielded drum core wirewound inductor manufactured by Bourns Inc., rated for 1.15 A with 109mOhm DC resistance. This component is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and production continuity. The part operates across -40°C to 100°C and is packaged in a nonstandard surface mount configuration measuring 4.50mm × 4.00mm × 4.60mm.

Key Parameters

Parameter	Value
Inductance	4.7 µH
Tolerance	±20%
Current Rating	1.15 A
DC Resistance (DCR)	109mOhm
Shielding	Unshielded
Core Material	Ferrite
Mounting Type	Surface Mount
Operating Temperature Range	-40°C ~ 100°C
Self Resonant Frequency	49 MHz
Package Dimensions	4.50mm L × 4.00mm W × 4.60mm H

Substitute Part Grouping Explanation

Substitution eligibility for the PM43-4R7M is determined by the following critical parameters: inductance value (4.7 µH ±20%), core material (ferrite), shielding configuration (unshielded), current rating capability (minimum 1.15 A), DC resistance compatibility, surface mount packaging, and physical dimensions. Parts are classified into two categories:

Direct Substitutes: Parts meeting all electrical specifications and physical constraints with equal or superior performance characteristics.

Similar Substitutes: Parts matching core electrical parameters but originating from alternative manufacturers, requiring verification of mechanical fit and thermal performance within the application's operating envelope.

Parameter Comparison

Parameter	PM43-4R7M	SDR0403-4R7ML	CR43NP-4R7MC	SRR1806-681M
Manufacturer	Bourns Inc.	Bourns Inc.	Sumida America Components Inc.	Bourns Inc.
Inductance	4.7 µH	4.7 µH	4.7 µH	680 µH
Tolerance	±20%	±20%	±20%	±20%
Current Rating	1.15 A	1.7 A	1.15 A	540 mA
DC Resistance	109mOhm	94mOhm Max	108.7mOhm Max	1.47Ohm
Shielding	Unshielded	Unshielded	Unshielded	Shielded
Core Material	Ferrite	Ferrite	Ferrite	Ferrite
Operating Temperature	-40°C ~ 100°C	-40°C ~ 125°C	-40°C ~ 100°C	-40°C ~ 125°C
Self Resonant Frequency	49 MHz	50 MHz	49.3 MHz	2.1 MHz
Product Status	Obsolete	Active	Active	Active
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Package Dimensions	4.50mm L × 4.00mm W × 4.60mm H	4.50mm L × 4.00mm W × 4.60mm H	4.80mm L × 4.30mm W × 4.60mm H	18.30mm L × 14.00mm W × 7.10mm H

Engineering Selection Recommendations

SDR0403-4R7ML is the primary direct substitute for PM43-4R7M applications. This Bourns Inc. component maintains identical inductance (4.7 µH) and tolerance (±20%), with superior current rating (1.7 A versus 1.15 A) and lower DC resistance (94mOhm Max versus 109mOhm). The SDR0403-4R7ML is ROHS3 compliant and rated to -40°C ~ 125°C, extending the operating temperature range. Physical dimensions and mounting type are identical, ensuring direct PCB compatibility. Product status is active with established supply chain availability.

CR43NP-4R7MC from Sumida America Components Inc. provides an alternative substitute matching the original current rating (1.15 A) and DC resistance specification (108.7mOhm Max). Inductance, tolerance, and self-resonant frequency are equivalent. This part is ROHS3 compliant and active in production. Physical dimensions differ slightly (4.80mm L × 4.30mm W versus 4.50mm L × 4.00mm W), requiring verification of PCB layout constraints and available mounting space.

SRR1806-681M is not suitable as a substitute. Although manufactured by Bourns Inc. and ROHS3 compliant, this component specifies 680 µH inductance, which deviates fundamentally from the 4.7 µH requirement. The significantly lower current rating (540 mA) and higher DC resistance (1.47Ohm) make this part incompatible with the original application parameters. The shielded configuration and substantially larger package footprint (18.30mm × 14.00mm) further preclude direct substitution.

Frequently Asked Questions (FAQ)

Q: Can SDR0403-4R7ML directly replace PM43-4R7M without circuit modification?

A: Yes. SDR0403-4R7ML maintains identical inductance value (4.7 µH ±20%), tolerance, shielding configuration, and package dimensions. The higher current rating (1.7 A) and lower DC resistance (94mOhm Max) represent performance improvements compatible with the original design. ROHS3 compliance and extended temperature range (-40°C ~ 125°C) provide additional benefits.

Q: What are the physical compatibility constraints when considering CR43NP-4R7MC?

A: CR43NP-4R7MC dimensions are 4.80mm L × 4.30mm W × 4.60mm H, compared to PM43-4R7M at 4.50mm L × 4.00mm W × 4.60mm H. The height remains identical, but length and width increase by 0.30mm and 0.30mm respectively. PCB layout must accommodate this dimensional variance. Verify available mounting space and clearance to adjacent components before implementation.

Q: Why is SRR1806-681M listed as a substitute if it cannot replace PM43-4R7M?

A: SRR1806-681M appears in the original part's substitute list but does not meet substitution criteria for PM43-4R7M. The 680 µH inductance value is fundamentally incompatible with the 4.7 µH requirement. This part is suitable only for applications specifically requiring 680 µH inductance with 540 mA current capability.

Q: What compliance advantages do the substitute parts offer?

A: Both SDR0403-4R7ML and CR43NP-4R7MC are ROHS3 compliant, whereas PM43-4R7M is RoHS non-compliant. For applications subject to RoHS directives or customer compliance requirements, either substitute part satisfies regulatory obligations. All three parts are REACH unaffected and classified as EAR99 for export control purposes.

Q: How do temperature operating ranges affect part selection?

A: PM43-4R7M operates -40°C ~ 100°C. SDR0403-4R7ML and SRR1806-681M extend this to -40°C ~ 125°C, providing 25°C additional margin at the upper temperature limit. CR43NP-4R7MC maintains the original -40°C ~ 100°C range. Select SDR0403-4R7ML for applications requiring extended high-temperature performance.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message