SSQ 1 Equivalent & Substitute Parts

Part Overview

The SSQ 1 is a 1 A, 125 V AC/DC surface mount board mount fuse manufactured by Bel Fuse Inc. in a 2-SMD, Square End Block package. This component is classified as Obsolete, making identification of equivalent and substitute parts essential for ongoing design support and production continuity. Substitute parts must maintain electrical equivalence across current rating, voltage rating, response time, and mechanical compatibility while meeting the same regulatory approvals and environmental specifications.

Substiute Parts

SSQ 1

Bel Fuse Inc.In Stock: 751SSQ 1 Datasheet

Current PartRFQ

0679L1000-01

Bel Fuse Inc.In Stock: 105750679L1000-01 Datasheet

DirectRFQ

0476001.MR

Littelfuse Inc.In Stock: 14110476001.MR Datasheet

DirectRFQ

0476001.MRSN

Littelfuse Inc.In Stock: 43730476001.MRSN Datasheet

DirectRFQ

0451001.MRL

Littelfuse Inc.In Stock: 1802730451001.MRL Datasheet

SimilarRFQ

0451001.MRSN

Littelfuse Inc.In Stock: 18100451001.MRSN Datasheet

SimilarRFQ

0453001.MR

Littelfuse Inc.In Stock: 211270453001.MR Datasheet

SimilarRFQ

3404.0009.11

SCHURTER Inc.In Stock: 25863404.0009.11 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SSQ 1 are classified into two categories based on electrical and mechanical compatibility:

Direct Substitutes maintain identical electrical specifications (1 A, 125 V AC/DC, Fast Blow response) and mechanical form factor (2-SMD, Square End Block). These parts are interchangeable at the circuit level with no design modification required.

Similar Substitutes maintain identical electrical specifications (1 A, 125 V AC/DC, Fast Blow response) but may differ in package case style (J-Lead vs. Square End Block) or have enhanced voltage ratings (250 V AC). These parts require mechanical and thermal validation before implementation.

The following parameters determine substitution eligibility:

• Current Rating: 1 A (mandatory)
• Voltage Rating - AC: 125 V minimum
• Voltage Rating - DC: 125 V minimum
• Response Time: Fast Blow (mandatory)
• Mounting Type: Surface Mount (mandatory)
• Operating Temperature Range: -55°C ~ 125°C (mandatory)
• RoHS Status: ROHS3 Compliant (mandatory)

Parameter Comparison

Engineering Selection Recommendations

Direct Substitution (Recommended for Immediate Replacement)

The 0679L1000-01 from Bel Fuse Inc. is the primary direct substitute for the SSQ 1. Both parts share identical electrical specifications (1 A, 125 V AC/DC, Fast Blow) and mechanical form factor (2-SMD, Square End Block). The 0679L1000-01 is Active status with higher inventory availability (10,509 pcs) compared to the obsolete SSQ 1. This part maintains full electrical and mechanical compatibility with no circuit redesign required.

Alternative Substitutes (Active Status, Littelfuse NANO²® Series)

The 0451001.MRL and 0451001.MRSN from Littelfuse Inc. provide electrical equivalence (1 A, 125 V AC/DC, Fast Blow) with identical mechanical form factor. Both are Active status with substantial inventory. The 0451001.MRL is available in Cut Tape & Digi-Reel® packaging (180,200 pcs), matching the original SSQ 1 packaging format. The 0451001.MRSN is available in Tape & Reel format (1,766 pcs).

The 0453001.MR from Littelfuse Inc. (NANO²® 453 series) also provides full electrical equivalence with identical mechanical compatibility and is Active status with high inventory (21,088 pcs) in Tape & Reel packaging.

Enhanced Voltage Rating Option

The 0476001.MR and 0476001.MRSN from Littelfuse Inc. (NANO²® 476 series) provide enhanced AC voltage rating (250 V AC vs. 125 V AC) while maintaining 1 A current rating and 125 V DC rating. These parts are suitable for applications requiring higher AC voltage margin. Both are Active status with good inventory availability.

Mechanical Variant (J-Lead Package)

The 3404.0009.11 from SCHURTER Inc. (OMF 125 series) maintains electrical equivalence but uses a J-Lead package case instead of Square End Block. This part requires mechanical and thermal validation for PCB layout compatibility before implementation.

Frequently Asked Questions (FAQ)

Q: Can the 0679L1000-01 be used as a direct replacement for the SSQ 1?

A: Yes. The 0679L1000-01 maintains identical electrical specifications (1 A, 125 V AC/DC, Fast Blow response) and mechanical form factor (2-SMD, Square End Block). No circuit modification is required. The primary difference is packaging format (Tape & Reel vs. Cut Tape & Digi-Reel®).

Q: What is the difference between the Littelfuse NANO²® 451, 453, and 476 series substitutes?

A: All three series maintain the required 1 A, 125 V AC/DC, Fast Blow electrical specifications. The 451 and 453 series are electrically identical with 125 V AC rating. The 476 series provides enhanced 250 V AC rating, suitable for higher voltage applications. All use identical 2-SMD, Square End Block mechanical form factor.

Q: Can the 3404.0009.11 from SCHURTER be used as a substitute?

A: The 3404.0009.11 provides electrical equivalence (1 A, 125 V AC/DC, Fast Blow) but uses a J-Lead package case instead of Square End Block. PCB layout and thermal characteristics must be validated before implementation due to different mechanical form factor.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts are ROHS3 Compliant, matching the original SSQ 1 specification.

Q: What packaging formats are available for substitutes?

A: Substitute parts are available in multiple packaging formats: Tape & Reel (TR), Cut Tape & Digi-Reel® (CT), and Bulk. Selection depends on production volume and assembly process requirements.

Q: Do the substitute parts have the same operating temperature range?

A: Yes. All substitute parts operate across the -55°C ~ 125°C temperature range, matching the SSQ 1 specification.