V420PA40C Equivalent & Substitute Parts

Part Overview

The V420PA40C is a 680 V varistor manufactured by Littelfuse Inc., designed for transient voltage suppression in chassis mount applications. This component features a base mount configuration with a surge current rating of 6.5 kA and energy dissipation capacity of 170 J. The product is classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

Substiute Parts

V420PA40C

Littelfuse Inc.In Stock: 838V420PA40C Datasheet

Current PartRFQ

V421DB40

Littelfuse Inc.In Stock: 1114V421DB40 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the V420PA40C is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Maximum AC Volts: 420 V (must match)
• Maximum DC Volts: 560 V (must match)
• Varistor Voltage (Typical): 680 V (must match)
• Number of Circuits: 1 (must match)
• Operating Temperature Range: -55°C to 85°C (must match or exceed)

Mechanical Compatibility Criteria:

• Mounting Type: Chassis Mount (must match)
• Category: Transient Voltage Suppressors (TVS) (must match)

Performance Enhancement Parameters (allowable variance):

• Current - Surge: May increase from 6.5 kA (enhanced capability acceptable)
• Energy Dissipation: May increase from 170 J (enhanced capability acceptable)
• Capacitance @ Frequency: May vary with package type
• Package / Case: May differ if mechanical mounting compatibility is maintained

The V421DB40 qualifies as a direct substitute based on matching all critical electrical parameters while providing enhanced surge current handling (40 kA vs. 6.5 kA) and increased energy dissipation (600 J vs. 170 J).

Parameter Comparison

Engineering Selection Recommendations

The V421DB40 is the manufacturer-recommended substitute for the obsolete V420PA40C. Both components maintain identical electrical specifications for maximum AC/DC voltage ratings and nominal varistor voltage, ensuring functional compatibility in existing circuit designs.

The V421DB40 offers significant advantages in product lifecycle status and regulatory compliance. As an active product, it ensures long-term availability and supply chain continuity. The component achieves ROHS3 compliance, whereas the V420PA40C is non-compliant, making the V421DB40 the appropriate choice for new designs and systems requiring regulatory adherence.

The enhanced surge current rating (40 kA vs. 6.5 kA) and increased energy dissipation capacity (600 J vs. 170 J) of the V421DB40 provide improved transient protection margins without compromising electrical compatibility. The blade type encased package differs mechanically from the base mount configuration; however, both maintain chassis mount compatibility and identical circuit functionality.

Frequently Asked Questions (FAQ)

Q: Can the V421DB40 directly replace the V420PA40C in existing designs?

A: Yes. Both components share identical maximum AC voltage (420 V), maximum DC voltage (560 V), and nominal varistor voltage (680 V) specifications. The electrical performance is compatible for transient voltage suppression applications. Physical mounting differences require mechanical evaluation of the chassis mount interface.

Q: What is the significance of the higher surge current rating in the V421DB40?

A: The V421DB40 provides a 40 kA surge current capability compared to the V420PA40C's 6.5 kA rating. This represents enhanced transient protection capacity. The higher rating does not create incompatibility; it provides additional safety margin for transient events.

Q: How do the package differences affect substitution?

A: The V420PA40C uses a base mount configuration, while the V421DB40 employs a blade type encased package. Both are chassis mount designs. Mechanical compatibility must be confirmed based on the specific mounting structure and available space in the application. Electrical performance is unaffected by package type differences.

Q: Why is RoHS compliance relevant for this substitution?

A: The V420PA40C is RoHS non-compliant, while the V421DB40 achieves ROHS3 compliance. For new designs, regulatory requirements, or systems subject to environmental standards, the V421DB40 is the appropriate selection. For legacy system maintenance, either component may be acceptable depending on application requirements.

Q: Are there any operating temperature limitations?

A: Both components operate across the identical temperature range of -55°C to 85°C. No temperature-related constraints affect substitution.

Q: What inventory status should influence component selection?

A: The V420PA40C is obsolete with 736 units in stock. The V421DB40 is an active product with 1081 units available. For long-term system support and new implementations, the V421DB40 ensures ongoing availability and supply chain reliability.