ST-1000-ALT-SG Equivalent & Substitute Parts

Part Overview

The ST-1000-ALT-SG is a Gas Discharge Tube (GDT) rated for 1000V DC spark-over voltage with 2-pole through-hole configuration, manufactured by Bourns Inc. under the Sparctube™ ST-1000 series. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and component procurement.

Gas Discharge Tubes serve as surge protection devices in electronic circuits, providing rapid voltage clamping during transient overvoltage events. The obsolete status of the ST-1000-ALT-SG necessitates sourcing of equivalent components that maintain the same electrical performance and mechanical compatibility.

Substiute Parts

ST-1000-ALT-SG

Bourns Inc.In Stock: 905ST-1000-ALT-SG Datasheet

Current PartRFQ

CG31.0LTR

LittelfuseIn Stock: 1740CG31.0LTR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ST-1000-ALT-SG is determined by the following critical parameters:

• Voltage Rating Match: DC spark-over voltage must be 1000V to maintain circuit protection thresholds
• Pole Configuration: 2-pole requirement ensures compatibility with the original circuit topology
• Mounting Compatibility: Through-hole mounting with axial cylinder package ensures mechanical fit in existing PCB layouts
• Fail Mode: Non-fail-short characteristic must be preserved for safety-critical applications
• Regulatory Compliance: ROHS3 compliance required for environmental and supply chain standards

The CG31.0LTR from Littelfuse meets all substitution criteria within these parameters.

Parameter Comparison

Engineering Selection Recommendations

The CG31.0LTR is the direct functional equivalent for ST-1000-ALT-SG replacement. Selection is based on:

• Electrical Equivalence: Identical 1000V DC spark-over voltage and 2-pole configuration ensure drop-in compatibility
• Mechanical Compatibility: Axial cylinder through-hole package maintains existing PCB layout without modification
• Product Availability: CG31.0LTR is active production status with confirmed inventory, addressing the obsolescence of the original part
• Regulatory Alignment: Both components maintain ROHS3 compliance and REACH unaffected status, supporting supply chain continuity
• Discharge Performance: CG31.0LTR specifies 5kA impulse discharge current, providing defined surge handling capability

Frequently Asked Questions (FAQ)

Q: Can CG31.0LTR be used as a direct replacement for ST-1000-ALT-SG?

A: Yes. Both components share identical voltage rating (1000V), pole configuration (2-pole), mounting type (through-hole), and package form (axial cylinder). No circuit modifications are required.

Q: What is the significance of the impulse discharge current specification?

A: The CG31.0LTR specifies 5kA impulse discharge current (8/20µs waveform), defining the surge current capacity during transient events. The ST-1000-ALT-SG does not specify this parameter in available documentation.

Q: Are there packaging differences between these components?

A: The ST-1000-ALT-SG packaging is not specified. The CG31.0LTR is supplied in Cut Tape (CT) packaging. Both use identical axial cylinder case geometry for PCB mounting.

Q: Do both components meet current environmental standards?

A: Yes. Both ST-1000-ALT-SG and CG31.0LTR are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component procurement.

Q: Why is the ST-1000-ALT-SG obsolete?

A: Obsolescence reflects discontinuation by the manufacturer. The CG31.0LTR remains in active production, providing long-term supply chain stability for this voltage class and configuration.