SPD125R-105M Equivalent & Substitute Parts

Part Overview

The SPD125R-105M is a 1 mH shielded drum core wirewound inductor manufactured by API Delevan Inc., designed for surface mount applications with a 400 mA current rating and 2Ohm maximum DC resistance. This component is classified as Active product status and is RoHS3 compliant. Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the specified parameter tolerances for the application.

Key Parameters

Parameter	Value	Unit
Inductance	1	mH
Current Rating	400	mA
DC Resistance (Max)	2	Ohm
Shielding	Shielded	—
Core Material	Ferrite	—
Mounting Type	Surface Mount	—
Operating Temperature Range	-55°C to 125°C	—
Package Type	Nonstandard	—

Substitute Part Grouping Explanation

Substitute parts for the SPD125R-105M are identified based on the following critical parameters:

Primary Matching Criteria:

Inductance value: 1 mH (exact match required)
Core type: Ferrite drum core, shielded construction
Mounting: Surface mount technology
DC resistance: Maximum 2.3 Ohm (within acceptable tolerance for circuit performance)
Current rating: Minimum 300 mA (acceptable for applications rated up to 400 mA with thermal margin consideration)

Compliance Requirements:

RoHS3 compliance status
Operating temperature range compatibility
Moisture sensitivity level MSL 1

The SRR1206-102KL from Bourns Inc. meets these substitution criteria with equivalent inductance, shielded ferrite core construction, and surface mount packaging.

Parameter Comparison

Parameter	SPD125R-105M (API Delevan)	SRR1206-102KL (Bourns)	Compatibility Notes
Inductance	1 mH	1 mH	Exact match
Inductance Tolerance	±20%	±10%	Substitute has tighter tolerance
Current Rating	400 mA	300 mA	Substitute rated lower; verify application current requirements
Current - Saturation (Isat)	400 mA	540 mA	Substitute has higher saturation current
DC Resistance (Max)	2 Ohm	2.3 Ohm	Substitute within acceptable range; 0.3 Ohm increase
Shielding	Shielded	Shielded	Equivalent
Core Material	Ferrite	Ferrite	Equivalent
Operating Temperature	-55°C to 125°C	-40°C to 125°C	Substitute has narrower lower temperature range
Mounting Type	Surface Mount	Surface Mount	Equivalent
Package / Case	Nonstandard	Nonstandard	Both nonstandard; verify PCB footprint compatibility
Size / Dimension (L x W)	0.472" x 0.472" (12.00mm x 12.00mm)	0.500" x 0.500" (12.70mm x 12.70mm)	Substitute 0.7mm larger in each dimension
Height - Seated (Max)	0.236" (6.00mm)	0.256" (6.50mm)	Substitute 0.5mm taller
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	Equivalent
Moisture Sensitivity Level	MSL 1 (Unlimited)	MSL 1 (Unlimited)	Equivalent

Engineering Selection Recommendations

Primary Part (SPD125R-105M): Use the original SPD125R-105M when the application requires the full 400 mA current rating and the lower operating temperature limit of -55°C. This part is Active status with full RoHS3 and REACH compliance.

Substitute Part (SRR1206-102KL): The SRR1206-102KL from Bourns Inc. is suitable as a substitute when:

Application current requirements do not exceed 300 mA continuous operation
Operating temperature range of -40°C to 125°C is acceptable
PCB layout can accommodate the 0.7mm larger footprint (12.70mm x 12.70mm vs. 12.00mm x 12.00mm)
The additional 0.5mm height (6.50mm vs. 6.00mm) does not conflict with assembly constraints
The 0.3 Ohm increase in DC resistance (2.3 Ohm vs. 2 Ohm) is acceptable for circuit performance

Both parts maintain RoHS3 compliance, MSL 1 rating, and equivalent shielded ferrite core construction.

Frequently Asked Questions (FAQ)

Q: Can the SRR1206-102KL replace the SPD125R-105M in all applications?

A: No. The SRR1206-102KL has a lower current rating (300 mA vs. 400 mA). Substitution is valid only when the application current requirement does not exceed 300 mA. Additionally, verify that the operating temperature range of -40°C to 125°C meets your application needs, as the original part operates down to -55°C.

Q: What are the physical compatibility considerations?

A: The SRR1206-102KL is larger in all dimensions: 0.7mm wider and longer (12.70mm vs. 12.00mm) and 0.5mm taller (6.50mm vs. 6.00mm). Verify that your PCB layout and assembly clearances accommodate these differences before substitution.

Q: How does the DC resistance difference affect circuit performance?

A: The SRR1206-102KL has a maximum DC resistance of 2.3 Ohm compared to 2 Ohm for the SPD125R-105M. This 0.3 Ohm increase results in additional power dissipation. Calculate the impact on your circuit: Power loss = I² × R. For a 300 mA application, the difference is approximately 27 mW. Verify this is acceptable for your thermal design.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the SPD125R-105M and SRR1206-102KL are RoHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating.

Q: What is the inductance tolerance difference?

A: The SPD125R-105M has ±20% tolerance, while the SRR1206-102KL has ±10% tolerance. The substitute part offers tighter inductance tolerance, which may be beneficial for precision applications.

Q: Can I use the SRR1206-102KL in applications requiring -55°C operation?

A: No. The SRR1206-102KL is rated for -40°C to 125°C. If your application requires operation at -55°C, the original SPD125R-105M must be used.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message