Equivalent & Substitute Parts for 3KP33C

Part Overview

The 3KP33C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse, designed for general-purpose voltage protection applications. This axial-leaded, through-hole component operates with a 33V reverse standoff voltage and provides 3kW peak pulse power protection. The product is currently obsolete, making identification of suitable substitute components essential for ongoing system maintenance, repairs, and new designs requiring equivalent protection characteristics.

Substiute Parts

3KP33C

LittelfuseIn Stock: 9873KP33C Datasheet

Current PartRFQ

5KP33CA

HY Electronic (Cayman) LimitedIn Stock: 118415KP33CA Datasheet

DirectRFQ

5KP33CA-TP

Micro Commercial CoIn Stock: 168145KP33CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3KP33C is determined by the following critical parameters:

• Voltage Rating Match: Reverse standoff voltage of 33V is the primary selection criterion. Substitute parts must maintain this voltage class to ensure proper circuit protection without nuisance triggering.
• Package Compatibility: Through-hole axial mounting is required for direct board-level replacement. Substitute parts must use compatible axial packages (P600 or R-6).
• Power Handling Capability: Peak pulse power rating must meet or exceed the original 3000W specification to maintain protection adequacy.
• Clamping Voltage: The maximum clamping voltage determines transient suppression effectiveness. Substitute parts with lower clamping voltages provide enhanced protection margins.
• Bidirectional Operation: Single-channel bidirectional configuration must be preserved for AC or dual-polarity protection applications.

The identified substitutes—5KP33CA and 5KP33CA-TP—share the same 33V voltage rating and axial through-hole mounting, with enhanced power handling (5000W) and improved clamping characteristics compared to the obsolete 3KP33C.

Parameter Comparison

Engineering Selection Recommendations

Both 5KP33CA and 5KP33CA-TP are active, production-status components suitable for replacing the obsolete 3KP33C. Selection between these two substitutes depends on application-specific requirements:

5KP33CA-TP (Micro Commercial Co) is the manufacturer-recommended substitute. This part maintains the full operating temperature range (-55°C to 175°C) matching the original 3KP33C, ensuring compatibility in high-temperature environments. It is supplied in Cut Tape packaging and carries ROHS3 compliance with REACH Unaffected status.

5KP33CA (HY Electronic) provides equivalent voltage protection with enhanced current handling (93.9A peak pulse) and higher power dissipation (5000W). However, the operating temperature range is limited to -55°C to 150°C, which may restrict use in applications requiring the full 175°C upper limit of the original component.

Both substitutes feature improved clamping voltage (53.3V versus 55.97V), providing superior transient suppression. The R-6 axial package used by both substitutes is mechanically compatible with through-hole PCB layouts designed for the P600 package.

Frequently Asked Questions (FAQ)

Q: Can 5KP33CA and 5KP33CA-TP be used interchangeably?

A: Both parts share identical electrical specifications (33V rating, 53.3V clamping, 5000W power handling) and R-6 axial packaging. The primary difference is operating temperature range: 5KP33CA-TP supports -55°C to 175°C, while 5KP33CA is rated to -55°C to 150°C. Selection depends on application temperature requirements.

Q: Is the R-6 package compatible with P600 footprints?

A: Both P600 and R-6 are axial through-hole packages with compatible lead spacing for standard PCB designs. Physical dimensions may vary slightly, but both are suitable for through-hole mounting in applications originally designed for the 3KP33C.

Q: Why do the substitute parts have lower clamping voltage?

A: The 5KP series substitutes clamp at 53.3V compared to the 3KP33C's 55.97V. Lower clamping voltage provides improved transient suppression performance, reducing voltage stress on protected circuits while maintaining the same 33V standoff rating.

Q: Are these substitutes RoHS compliant?

A: Yes, both 5KP33CA and 5KP33CA-TP are ROHS3 compliant, meeting environmental and regulatory requirements equivalent to the original 3KP33C.

Q: What is the difference between Cut Tape and standard packaging?

A: 5KP33CA-TP is supplied in Cut Tape (CT) packaging, suitable for automated assembly processes. 5KP33CA uses standard packaging. Both contain identical components; packaging format affects handling and assembly methodology only.