SG320 Inrush Current Limiter - Equivalent & Substitute Parts

Part Overview

The SG320 is an active inrush current limiter manufactured by Ametherm, part of the SURGE-GARD™ series. This component is designed to limit inrush current in power supply circuits and related applications. The SG320 operates at 16 Ohms with ±25% tolerance and supports a steady-state maximum current of 4 A. The part is currently in active production status with 668 units in stock. Finding equivalent or substitute parts may be necessary due to supply chain considerations, lead time requirements, or specific application constraints.

Substiute Parts

SG320

AmethermIn Stock: 739SG320 Datasheet

Current PartRFQ

B57238S0160M000

EPCOS - TDK ElectronicsIn Stock: 803B57238S0160M000 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SG320 is determined by the following critical electrical and mechanical parameters:

• Resistance value: 16 Ohms (primary electrical specification)
• Tolerance: ±25% maximum allowable deviation
• Steady-state current rating: 4 A minimum
• Physical form factor: Diameter and lead spacing compatibility
• Regulatory compliance: RoHS3 compliance and approval agency certifications

The B57238S0160M000 qualifies as a substitute based on matching resistance (16 Ohms), current rating (4 A), and RoHS3 compliance. Dimensional differences exist but do not preclude functional substitution in applications where mechanical constraints permit.

Parameter Comparison

Engineering Selection Recommendations

Both the SG320 and B57238S0160M000 maintain active production status and meet RoHS3 compliance requirements. The B57238S0160M000 offers a tighter tolerance specification (±20% versus ±25%), which may provide improved performance consistency in applications requiring higher precision. Both parts carry regulatory approvals from recognized agencies (CSA/UR for SG320; UL for B57238S0160M000).

The primary consideration for selection is mechanical fit. The B57238S0160M000 features a smaller diameter (16.00mm versus 19.05mm) and reduced lead spacing (7.50mm versus 8.89mm). Verify that the substitute part's physical dimensions are compatible with the PCB layout and mechanical assembly constraints of the target application before implementation.

Frequently Asked Questions (FAQ)

Q: Can the B57238S0160M000 directly replace the SG320 in all applications?

A: Electrical compatibility is established through matching resistance (16 Ohms) and current rating (4 A). However, mechanical compatibility must be verified. The B57238S0160M000 has a smaller diameter and reduced lead spacing. Confirm that the PCB footprint and mechanical clearances accommodate these dimensional differences.

Q: What is the significance of the tolerance difference between ±25% and ±20%?

A: The B57238S0160M000 tolerance of ±20% represents a tighter specification than the SG320's ±25%. This means the B57238S0160M000 will maintain resistance values closer to the nominal 16 Ohms across the specified operating range, which may be beneficial in applications requiring higher precision current limiting.

Q: Are both parts compliant with environmental and regulatory standards?

A: Yes. Both the SG320 and B57238S0160M000 are ROHS3 compliant and REACH unaffected. The SG320 carries CSA and UR approvals, while the B57238S0160M000 carries UL approval. Verify that the specific approval agency certifications required by your application are met by the selected part.

Q: What inventory considerations should be factored into the selection?

A: The SG320 has 668 units in stock, while the B57238S0160M000 has 771 units available. Both parts are in active production, supporting long-term availability for production and maintenance requirements.

Q: How do the lead spacing differences affect circuit design?

A: The SG320 has 0.350" (8.89mm) lead spacing, while the B57238S0160M000 has 0.295" (7.50mm) spacing. This difference requires PCB layout modification if substituting between parts. Verify that the target PCB design can accommodate the substitute part's lead spacing before committing to a design change.