SC312MF-220 Equivalent & Substitute Parts

Part Overview

The SC312MF-220 is a 22 µH shielded wirewound inductor manufactured by Signal Transformer, rated for 400 mA continuous current with a maximum DC resistance of 1.4 Ohm. This component is classified as obsolete, making identification of compatible substitute parts essential for ongoing design support and production continuity. The part operates across the temperature range of -40°C to 125°C and is RoHS3 compliant.

Substiute Parts

SC312MF-220

Signal TransformerIn Stock: 719SC312MF-220 Datasheet

Current PartRFQ

1229AS-H-220M=P3

Murata ElectronicsIn Stock: 54231229AS-H-220M=P3 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SC312MF-220 is determined by the following critical parameters:

• Inductance Value: Must be 22 µH with ±20% tolerance
• Current Rating: Substitute must support minimum 400 mA continuous current
• DC Resistance: Lower DCR values are acceptable; higher values may impact circuit performance
• Shielding: Shielded construction required to maintain electromagnetic isolation
• Mounting Type: Surface mount configuration mandatory
• Package Dimensions: Physical footprint must be compatible with board layout constraints
• Operating Temperature: Substitute must cover the required temperature range or be suitable for the application's actual operating conditions
• Compliance: RoHS3 compliance required for regulatory alignment

The Murata Electronics 1229AS-H-220M=P3 meets these substitution criteria with equivalent inductance, higher current rating capability, lower DC resistance, and active product status.

Parameter Comparison

Engineering Selection Recommendations

The 1229AS-H-220M=P3 from Murata Electronics is a direct functional substitute for the obsolete SC312MF-220. Key advantages include:

• Active Product Status: Murata part is in active production, ensuring long-term availability and supply chain stability
• Improved DC Resistance: 672 mOhm DCR versus 1.4 Ohm reduces power dissipation and heat generation
• Higher Current Rating: 530 mA rating exceeds the 400 mA requirement of the original design
• Compliance Alignment: Both parts maintain RoHS3 compliance and MSL 1 rating
• Physical Compatibility: Dimensions are within acceptable tolerance for standard PCB layouts (3.70mm x 3.90mm versus 3.80mm x 3.80mm)

The primary design consideration is the operating temperature range. The Murata substitute operates to 85°C maximum, compared to 125°C for the original part. Applications requiring operation above 85°C must evaluate alternative solutions or confirm that actual operating conditions remain within the substitute's thermal limits.

Frequently Asked Questions (FAQ)

Q: Can the 1229AS-H-220M=P3 be used as a direct replacement for SC312MF-220?

A: Yes, for applications operating at or below 85°C. Both parts share identical inductance values (22 µH ±20%), equivalent shielding, surface mount configuration, and RoHS3 compliance. The substitute offers superior DC resistance (672 mOhm versus 1.4 Ohm) and higher current rating (530 mA versus 400 mA).

Q: What is the impact of the lower operating temperature maximum on the Murata part?

A: The Murata substitute is rated to 85°C maximum, while the original Signal Transformer part operates to 125°C. If your application requires sustained operation above 85°C, the substitute is not suitable without thermal management modifications or alternative component selection.

Q: Are the physical dimensions compatible with existing PCB layouts?

A: The Murata part measures 3.70mm x 3.90mm with a maximum seated height of 1.20mm, compared to the original 3.80mm x 3.80mm with 1.35mm height. These dimensions are sufficiently close for standard surface mount assembly processes. Verify footprint compatibility with your specific PCB design before production implementation.

Q: What is the significance of the lower saturation current in the Murata part?

A: The Murata substitute has an Isat of 500 mA versus 640 mA for the original. Since your design operates at 400 mA continuous current, both parts maintain adequate saturation margin. The 100 mA difference does not impact circuit performance at the specified operating current.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the SC312MF-220 and 1229AS-H-220M=P3 are RoHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, ensuring regulatory alignment and storage flexibility.