SC312MF-1R5 Equivalent & Substitute Parts

Part Overview

The SC312MF-1R5 is a 1.5 µH shielded wirewound inductor manufactured by Signal Transformer, rated for 1.5 A continuous current with a maximum DC resistance of 104mOhm. This component is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and procurement continuity. The part operates across the industrial temperature range of -40°C to 125°C and is mounted as a surface mount device in a nonstandard 3.80mm × 3.80mm package footprint.

Substiute Parts

SC312MF-1R5

Signal TransformerIn Stock: 1159SC312MF-1R5 Datasheet

Current PartRFQ

1231AS-H-1R5N=P3

Murata ElectronicsIn Stock: 22431231AS-H-1R5N=P3 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SC312MF-1R5 is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Inductance value must be 1.5 µH at 100 kHz test frequency
• Shielding requirement must be maintained
• DC resistance must not exceed the application's thermal and efficiency limits
• Current rating must support the design's maximum operating current
• Saturation current must remain above the peak transient current levels

Mechanical Compatibility Criteria:

• Surface mount mounting type
• Package footprint dimensions must accommodate the PCB layout (3.80mm × 3.80mm nominal, with height ≤ 1.35mm preferred for space-constrained applications)
• Nonstandard package classification

Environmental & Compliance Criteria:

• Operating temperature range must cover -40°C to 125°C or be acceptable for the specific application thermal envelope
• RoHS3 compliance required
• Moisture sensitivity level MSL 1 acceptable

The substitute part 1231AS-H-1R5N=P3 meets these criteria with equivalent inductance, maintained shielding, superior current handling, and active product status.

Parameter Comparison

Engineering Selection Recommendations

The 1231AS-H-1R5N=P3 from Murata Electronics is the qualified substitute for the obsolete SC312MF-1R5. Selection of this alternative is supported by the following factors:

Product Status: The substitute is in active production status, ensuring long-term availability and supply chain stability compared to the obsolete original part.

Electrical Equivalence: Both parts maintain 1.5 µH inductance at 100 kHz with shielded construction. The substitute's lower DC resistance (42 mOhm vs. 104 mOhm) provides improved efficiency and reduced thermal dissipation.

Current Handling: The substitute's continuous current rating of 2.7 A exceeds the original 1.5 A specification. However, the saturation current of 2.1 A is lower than the original 2.5 A. Applications must verify that peak transient currents remain below 2.1 A to prevent saturation-induced inductance collapse.

Temperature Consideration: The substitute operates to 85°C maximum, compared to the original 125°C upper limit. Applications requiring operation above 85°C must conduct thermal analysis to confirm the substitute remains within acceptable operating margins.

Mechanical Fit: Package footprint dimensions are within standard PCB manufacturing tolerances (3.70mm × 3.90mm vs. 3.80mm × 3.80mm). The substitute's increased height of 1.80 mm (vs. 1.35 mm) requires verification of vertical clearance in the PCB assembly.

Compliance: Both parts maintain ROHS3 compliance and MSL 1 moisture sensitivity rating, ensuring compatibility with standard manufacturing and storage protocols.

Frequently Asked Questions (FAQ)

Q: Can the 1231AS-H-1R5N=P3 be used as a direct replacement for the SC312MF-1R5?

A: The 1231AS-H-1R5N=P3 is electrically and mechanically compatible for most applications. Verification is required for three specific conditions: (1) peak transient current must not exceed 2.1 A saturation current, (2) operating temperature must not exceed 85°C, and (3) vertical PCB clearance must accommodate the 1.80 mm seated height.

Q: What is the difference between the DC resistance values?

A: The substitute has 42 mOhm maximum DC resistance compared to the original 104 mOhm. Lower DC resistance reduces I²R losses and heat generation, improving circuit efficiency. This is a beneficial characteristic for most applications.

Q: Why does the substitute have a lower saturation current?

A: The substitute's saturation current of 2.1 A is lower than the original 2.5 A due to differences in core material and construction. Applications must ensure that peak transient currents remain below 2.1 A to maintain inductance stability and prevent core saturation.

Q: Are there packaging differences between these parts?

A: The original part packaging is not specified. The substitute is supplied in standard Tape & Reel (TR) format, which is the industry standard for surface mount components and simplifies procurement and assembly processes.

Q: What is the impact of the narrower temperature range on the substitute?

A: The substitute operates from -40°C to 85°C, compared to the original -40°C to 125°C. Applications operating above 85°C must verify that the substitute remains within acceptable performance margins through thermal analysis or testing.

Q: How do the package dimensions compare?

A: The substitute footprint is 3.70mm × 3.90mm versus the original 3.80mm × 3.80mm. These dimensions are within standard PCB manufacturing tolerances. The substitute height of 1.80 mm exceeds the original 1.35 mm by 0.45 mm, requiring clearance verification in space-constrained assemblies.

Q: Is the inductance tolerance difference significant?

A: The substitute has ±30% tolerance compared to the original ±20%. For applications requiring tighter inductance control, the wider tolerance of the substitute may require circuit compensation or selection of parts within a narrower tolerance band.