SLD33U-017 Equivalent & Substitute Parts

Part Overview

The SLD33U-017 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse, designed for transient overvoltage protection in electronic circuits. This component features a 33V reverse standoff voltage with a 53.3V maximum clamping voltage and 95.7A peak pulse current capability, housed in a P600 axial through-hole package. The part is actively produced, AEC-Q101 qualified for automotive applications, and RoHS3 compliant. Equivalent and substitute parts are identified for applications requiring alternative sourcing, packaging configurations, or inventory availability while maintaining electrical and mechanical compatibility within specified parameters.

Substiute Parts

SLD33U-017

LittelfuseIn Stock: 1564SLD33U-017 Datasheet

Current PartRFQ

5KP33A

Diotec SemiconductorIn Stock: 43285KP33A Datasheet

DirectRFQ

SA33A

Fairchild SemiconductorIn Stock: 21325SA33A Datasheet

MFR RecommendedRFQ

5KP33A-TP

Micro Commercial CoIn Stock: 12205KP33A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SLD33U-017 are qualified based on the following critical parameters that determine functional equivalence:

• Voltage - Reverse Standoff: 33V (identical across all substitutes)
• Voltage - Clamping (Max) @ Ipp: 53.3V (identical across all substitutes)
• Voltage - Breakdown (Min): 36.7V (identical across all substitutes)
• Type: Zener, Unidirectional (1 channel)
• Mounting Type: Through Hole
• Power - Peak Pulse: 5000W (5kW)
• RoHS3 Compliance and ECCN EAR99 classification

Substitutes are grouped by package configuration and current handling capability. The 5KP33A and 5KP33A-TP maintain full electrical equivalence with peak pulse current ratings of 94A and unspecified ratings respectively, both in P600 and R-6 axial packages. The SA33A represents a lower-current alternative (9.4A peak pulse) in a DO-15 package, suitable for lower-energy transient protection applications.

Parameter Comparison

Engineering Selection Recommendations

5KP33A (Diotec Semiconductor): This part maintains electrical equivalence with the SLD33U-017 across all critical voltage parameters and power rating. Peak pulse current of 94A provides functional parity for high-energy transient suppression. The P600 axial package ensures mechanical compatibility with existing PCB layouts. Product status is active with 4300 units in stock. Selection is appropriate for direct substitution in applications not requiring automotive AEC-Q101 qualification.

5KP33A-TP (Micro Commercial Co): This variant offers identical voltage specifications and 5000W power rating in an R-6 axial package. Operating temperature range matches the original part (-55 to 175°C). ROHS3 compliance and REACH unaffected status align with regulatory requirements. Product status is active with 1180 units available. Package configuration differs from the original P600, requiring PCB layout verification for mechanical fit.

SA33A (Fairchild Semiconductor): This part is marked obsolete and presents significant limitations for new designs. Peak pulse current of 9.4A and power rating of 500W are substantially lower than the original specification, restricting application to low-energy transient events only. The DO-15 package differs mechanically from P600, requiring board redesign. This part should be considered only for legacy system maintenance where original specifications are not critical.

Frequently Asked Questions (FAQ)

Q: Can the 5KP33A directly replace the SLD33U-017 without circuit modification?

A: Yes, the 5KP33A maintains identical voltage specifications (33V standoff, 53.3V clamping) and equivalent power rating (5000W). The P600 axial package is mechanically compatible. No circuit modifications are required for electrical function. Verify PCB layout accommodates the component orientation if needed.

Q: What is the primary difference between the 5KP33A and 5KP33A-TP?

A: Both parts share identical electrical specifications. The primary difference is package configuration: 5KP33A uses P600 axial package, while 5KP33A-TP uses R-6 axial package. Selection depends on PCB footprint requirements and available board space.

Q: Is the SA33A suitable as a substitute for the SLD33U-017?

A: The SA33A is not recommended as a direct substitute. While voltage parameters are identical, peak pulse current (9.4A) and power dissipation (500W) are approximately 10 times lower than the original part. This limits application to low-energy transient protection only. Additionally, the part is obsolete, making long-term availability uncertain. Use only for legacy system support where reduced transient energy is acceptable.

Q: What compliance certifications should I verify when selecting a substitute?

A: For automotive applications, verify AEC-Q101 qualification if required by system specifications. Confirm RoHS3 compliance status for regulatory adherence. The SLD33U-017 carries both certifications; substitute parts vary in compliance status. The 5KP33A and 5KP33A-TP maintain RoHS3 compliance, while the SA33A is obsolete and compliance status may be uncertain.

Q: Does operating temperature range affect part selection?

A: The SLD33U-017 operates from -55 to 175°C. The 5KP33A operates from -50 to 175°C, a 5°C difference at the lower limit. For applications requiring full -55°C operation, verify the 5KP33A meets system requirements. The 5KP33A-TP matches the full temperature range. Operating temperature specifications for SA33A are not provided.

Q: Can I use these parts interchangeably in high-current transient suppression circuits?

A: The 5KP33A and 5KP33A-TP are interchangeable for high-current applications (94A+ peak pulse). The SA33A is not suitable for high-current transient suppression due to its 9.4A peak pulse rating. Verify circuit transient energy requirements against part specifications before selection.