LVR040K Polymeric PTC Resettable Fuse - Equivalent & Substitute Parts

Part Overview

The LVR040K is a Polymeric PTC Resettable Fuse manufactured by Littelfuse Inc. in the PolySwitch® LVR series. This component is rated for 240V (265V internal) with a 400 mA hold current and is designed for through-hole radial mounting in disc configuration. The part is currently Active in product status with 1212 pieces in stock. PTC resettable fuses are essential overcurrent protection devices that automatically reset after a fault condition is cleared, eliminating the need for manual replacement. Finding equivalent parts is necessary to ensure supply chain continuity, optimize inventory management, and maintain design flexibility across manufacturing batches.

Substiute Parts

LVR040K

Littelfuse Inc.In Stock: 1235LVR040K Datasheet

Current PartRFQ

LVR040S-1

Littelfuse Inc.In Stock: 1798LVR040S-1 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LVR040K is determined by strict equivalence across the following critical parameters:

• Voltage rating: 240V (265V internal) maximum
• Current hold specification: 400 mA
• Current trip specification: 900 mA
• Maximum current capacity: 5.5 A
• Time to trip: 24 seconds
• Initial resistance: 600 mOhms minimum
• Post-trip resistance: 1.9 Ohms maximum
• Operating temperature range: -20°C to 85°C
• Mounting configuration: Through hole radial disc
• Lead spacing: 0.200" (5.08mm)
• Component type: Polymeric PTC resettable fuse
• Series family: PolySwitch® LVR

The LVR040S-1 meets all specified electrical and mechanical parameters and is classified as a direct manufacturer equivalent within the same product series and family.

Parameter Comparison

Engineering Selection Recommendations

Both LVR040K and LVR040S-1 are Active products from Littelfuse Inc. with identical electrical specifications and certifications (CQC, CSA, TUV, UL). Both components are ROHS3 compliant and carry the same ECCN and HTSUS classifications. The primary physical difference is the seated height: LVR040K measures 0.823" (20.90mm) while LVR040S-1 measures 0.768" (19.50mm). Selection between these parts should be based on available board space and PCB layout constraints. Both parts are suitable for direct substitution where the reduced height of LVR040S-1 does not create design conflicts.

Frequently Asked Questions (FAQ)

Q: Can LVR040S-1 be used as a direct replacement for LVR040K?

A: Yes. Both parts share identical electrical ratings, current specifications, temperature ranges, and certifications. The only difference is the seated height dimension. Substitution is valid provided the reduced height (19.50mm vs 20.90mm) is compatible with your PCB layout.

Q: What are the critical parameters that define substitution eligibility?

A: Substitution requires matching voltage rating (240V/265V internal), hold current (400 mA), trip current (900 mA), maximum current (5.5 A), trip time (24 s), initial resistance (600 mOhms), post-trip resistance (1.9 Ohms), operating temperature range (-20°C to 85°C), mounting type (through hole), package configuration (radial disc), and lead spacing (0.200"/5.08mm).

Q: Are there any compliance or certification differences between these parts?

A: No. Both LVR040K and LVR040S-1 carry identical approvals from CQC, CSA, TUV, and UL. Both are ROHS3 compliant and REACH unaffected.

Q: What is the significance of the height difference?

A: The seated height difference (0.823" for LVR040K versus 0.768" for LVR040S-1) affects vertical clearance on the PCB. The LVR040S-1 provides 0.055" (1.40mm) less height, which may be beneficial in space-constrained applications but must be verified against your specific board design.

Q: Are both parts currently available?

A: Yes. LVR040K has 1212 pieces in stock and LVR040S-1 has 1693 pieces in stock, both listed as new original inventory.