SLD18U-017-B Equivalent & Substitute Parts

Part Overview

The SLD18U-017-B is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for transient overvoltage protection in electronic circuits. This through-hole component operates with an 18V reverse standoff voltage and provides 5000W peak pulse power dissipation. The part maintains Active product status and carries AEC-Q101 automotive qualification, making it suitable for demanding industrial and automotive applications. Substitute parts are identified based on electrical parameter equivalence and mechanical compatibility to support procurement flexibility and supply chain continuity.

Substiute Parts

SLD18U-017-B

Littelfuse Inc.In Stock: 1135SLD18U-017-B Datasheet

Current PartRFQ

5KP18A

Diotec SemiconductorIn Stock: 42185KP18A Datasheet

MFR RecommendedRFQ

5KP18A-E3/54

Vishay General Semiconductor - Diodes DivisionIn Stock: 83655KP18A-E3/54 Datasheet

MFR RecommendedRFQ

5KP18A-TP

Micro Commercial CoIn Stock: 20485KP18A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SLD18U-017-B are qualified based on the following electrical and mechanical criteria:

Critical Matching Parameters:

• Voltage - Reverse Standoff: 18V (Typ)
• Voltage - Clamping (Max) @ Ipp: 29.2V
• Power - Peak Pulse: 5000W
• Unidirectional Zener type
• Through-hole axial mounting configuration
• RoHS3 compliance

Acceptable Variation Ranges:

• Current - Peak Pulse (10/1000µs): 171A to 174.7A (within 2% tolerance)
• Operating Temperature: -50°C to -55°C minimum; 175°C maximum
• Package variants: P600 and R-6 axial configurations are mechanically compatible

All substitute parts maintain Active product status and meet the electrical protection requirements of the original specification.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts maintain Active product status and ROHS3 compliance, ensuring regulatory alignment with the original SLD18U-017-B specification.

5KP18A (Diotec Semiconductor): Electrically equivalent with 171A peak pulse current and P600 axial package. Operating temperature minimum of -50°C is 5°C higher than the original part; applications requiring -55°C operation should confirm thermal performance.

5KP18A-E3/54 (Vishay General Semiconductor - Diodes Division): Fully equivalent across all critical parameters with 171A peak pulse current, P600 axial package, and -55°C to 175°C operating range matching the original specification. Carries TransZorb® series designation and identical compliance certifications.

5KP18A-TP (Micro Commercial Co): Electrically equivalent with 5000W power rating and -55°C to 175°C operating range. Package variant is R-6 axial configuration instead of P600; mechanical compatibility must be confirmed for the specific PCB layout and through-hole footprint.

Frequently Asked Questions (FAQ)

Q: Can I substitute the SLD18U-017-B with any of these parts directly?

A: Yes, all listed parts are electrically equivalent based on voltage, clamping, and power specifications. Mechanical compatibility depends on package type: P600 packages (5KP18A and 5KP18A-E3/54) are direct mechanical substitutes; R-6 package (5KP18A-TP) requires PCB footprint verification.

Q: What is the difference between P600 and R-6 axial packages?

A: Both are through-hole axial configurations for the same voltage and power class. P600 and R-6 differ in physical dimensions and lead spacing. Confirm your PCB design accommodates the selected package before procurement.

Q: Does the 5KP18A from Diotec work in applications requiring -55°C operation?

A: The Diotec 5KP18A specifies -50°C minimum operating temperature, which is 5°C higher than the original SLD18U-017-B. For applications with -55°C requirements, use the Vishay 5KP18A-E3/54 or Micro Commercial 5KP18A-TP, both rated to -55°C.

Q: Are all substitute parts RoHS3 compliant?

A: Yes, all substitute parts listed carry ROHS3 compliance certification, matching the original part's environmental and regulatory status.

Q: What is the peak pulse current difference between the original and substitutes?

A: The SLD18U-017-B specifies 174.7A peak pulse current. The 5KP18A variants specify 171A, representing a 1.7% reduction. Both values fall within acceptable tolerance for the 5000W power class and 18V voltage specification.