RHEF900-AP Polymeric PTC Resettable Fuse - Equivalent & Substitute Parts

Part Overview

The RHEF900-AP is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., rated for 16V at 9A hold current with through-hole radial disc mounting. This component is classified as obsolete, which necessitates identification of active equivalent parts for ongoing design support and procurement continuity. The RHEF900-AP belongs to the PolySwitch® RHEF series and maintains full compliance with ROHS3 and REACH standards.

Substiute Parts

RHEF900-AP

Littelfuse Inc.In Stock: 853RHEF900-AP Datasheet

Current PartRFQ

RHEF900

Littelfuse Inc.In Stock: 812RHEF900 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RHEF900-AP is determined by strict equivalence across the following critical parameters:

• Voltage rating: 16V maximum
• Current hold specification: 9A
• Current trip specification: 16.5A
• Mounting configuration: Through hole radial disc
• Physical dimensions: 0.650" L x 0.118" W with 0.199" lead spacing
• Thermal operating range: -40°C to 125°C
• Regulatory compliance: CSA, TUV, UL certifications

The RHEF900 qualifies as a direct substitute based on identical electrical characteristics, mechanical form factor, and regulatory approvals. The distinction between RHEF900-AP and RHEF900 is packaging format only (tape/reel versus bag), which does not affect functional performance or circuit compatibility.

Parameter Comparison

Engineering Selection Recommendations

The RHEF900 is the direct functional equivalent to the obsolete RHEF900-AP. Both components share identical electrical specifications, thermal ratings, mechanical dimensions, and regulatory certifications. The RHEF900 maintains active product status with Littelfuse Inc., ensuring ongoing availability and supply chain continuity.

Selection of RHEF900 over RHEF900-AP is justified by product lifecycle status. The RHEF900-AP designation indicates obsolescence, while RHEF900 represents the current active part number within the same PolySwitch® RHEF series. Both maintain ROHS3 compliance and full CSA, TUV, and UL approvals, confirming regulatory equivalence for applications requiring these certifications.

Frequently Asked Questions (FAQ)

Q: Can RHEF900 be used as a direct replacement for RHEF900-AP in existing designs?

A: Yes. The RHEF900 is electrically and mechanically identical to RHEF900-AP. All electrical parameters, thermal characteristics, physical dimensions, and regulatory certifications are equivalent. The only difference is packaging format (bag versus tape/reel), which does not affect circuit performance or PCB assembly compatibility.

Q: What is the difference between RHEF900-AP and RHEF900?

A: The suffix "-AP" on RHEF900-AP indicates a specific packaging configuration (tape/reel). RHEF900 uses bag packaging. The core component specifications, including voltage rating, current ratings, resistance values, and operating temperature range, are identical between both part numbers.

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

A: No. Both RHEF900-AP and RHEF900 carry identical regulatory approvals: CSA, TUV, and UL certifications. Both are ROHS3 compliant and REACH unaffected. Compliance status is equivalent for all applications requiring these certifications.

Q: Why is RHEF900-AP listed as obsolete?

A: RHEF900-AP has reached end-of-life status with Littelfuse Inc. The RHEF900 represents the active continuation of this product line. For new designs and ongoing procurement, RHEF900 is the recommended part number to ensure supply availability and manufacturer support.

Q: Will RHEF900 fit the same PCB footprint as RHEF900-AP?

A: Yes. Both parts use identical through-hole radial disc mounting with 0.199" lead spacing and 0.650" L x 0.118" W dimensions. PCB layouts designed for RHEF900-AP require no modification to accommodate RHEF900.