SL1122A450R Gas Discharge Tube - Equivalent & Substitute Parts

Part Overview

The SL1122A450R is a 3-pole gas discharge tube (GDT) rated for 450V DC spark-over voltage with 10kA impulse discharge current capacity. Designed for through-hole mounting in radial cylinder configuration, this component provides transient overvoltage protection in industrial and telecommunications applications.

The SL1122A450R is classified as obsolete. Locating equivalent substitute parts is necessary to maintain design continuity and ensure continued availability for new production runs and field replacements.

Substiute Parts

SL1122A450R

Littelfuse Inc.In Stock: 923SL1122A450R Datasheet

Current PartRFQ

SL1021A450R

Littelfuse Inc.In Stock: 1324SL1021A450R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SL1122A450R is based on electrical and mechanical parameter equivalence within the Littelfuse GDT product family. The following parameters must remain constant for functional interchangeability:

• Voltage rating: 450V DC spark-over
• Discharge current capacity: 10kA (8/20µs impulse)
• Pole configuration: 3-pole
• Mounting method: Through-hole
• Fail mode: Non-shorting
• Environmental compliance: ROHS3 Compliant

The SL1021A450R meets all these criteria and is classified as an active product, making it a direct functional equivalent despite differences in package geometry.

Parameter Comparison

Engineering Selection Recommendations

The SL1021A450R is the recommended substitute for the obsolete SL1122A450R. Both components share identical electrical specifications (450V spark-over, 10kA discharge current, 3-pole configuration) and environmental compliance certifications (ROHS3, MSL 1).

The primary difference is package geometry: the SL1122A450R uses a radial cylinder configuration, while the SL1021A450R employs an axial cylinder with radial bend leads. Both are through-hole mounted components with equivalent footprint compatibility in standard PCB designs.

The SL1021A450R carries active product status with established supply chain availability, making it the appropriate choice for new designs and production continuity.

Frequently Asked Questions (FAQ)

Q: Can the SL1021A450R be used as a direct replacement for the SL1122A450R?

A: Yes. Both components have identical electrical ratings (450V DC spark-over, 10kA impulse discharge current) and pole configuration (3-pole). The primary difference is lead geometry (radial versus axial with radial bend), which does not affect electrical performance in standard through-hole applications.

Q: What is the difference between radial and axial cylinder packages?

A: Radial cylinder packages have leads extending perpendicular to the component body. Axial cylinder packages with radial bend have leads that initially extend along the body axis, then bend radially for PCB insertion. Both mount through standard through-hole pads with equivalent electrical performance.

Q: Are there any compliance differences between these parts?

A: No. Both the SL1122A450R and SL1021A450R are ROHS3 compliant, carry MSL 1 (unlimited moisture sensitivity), and share identical ECCN (EAR99) and HTSUS classifications.

Q: Why is the SL1122A450R obsolete?

A: The SL1122A450R has been discontinued by Littelfuse Inc. The SL1021A450R remains in active production and provides equivalent electrical functionality for all 450V, 10kA, 3-pole GDT applications.

Q: What PCB layout considerations apply when switching from SL1122A450R to SL1021A450R?

A: Both components use through-hole mounting. Lead geometry differences (radial versus axial with radial bend) may require minor PCB pad repositioning, but electrical performance and protection characteristics remain identical. Verify pad spacing against component datasheets for your specific PCB design.