RHEF070 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The RHEF070 is an active polymeric PTC resettable fuse manufactured by Littelfuse in the PolySwitch® series. This component provides overcurrent protection with automatic reset capability in through-hole radial disc configuration. The part operates at a maximum voltage of 30V with a hold current of 700 mA and is designed for applications requiring reliable circuit protection with self-recovery characteristics. Finding equivalent or substitute parts may be necessary due to inventory constraints, lead time requirements, or specific application compatibility needs.

Substiute Parts

RHEF070

LittelfuseIn Stock: 3714RHEF070 Datasheet

Current PartRFQ

MF-RHT070-0

Bourns Inc.In Stock: 1508MF-RHT070-0 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for polymeric PTC resettable fuses is determined by the following critical parameters:

Mandatory Compatibility Parameters:

• Current - Hold (Ih) (Max): Must match or exceed the application requirement
• Current - Trip (It): Must align with circuit protection threshold
• Voltage - Max: Must equal or exceed the circuit operating voltage
• Operating Temperature Range: Must encompass the application environment
• Mounting Type: Must be Through Hole for PCB compatibility
• Package / Case: Must be Radial, Disc configuration for mechanical fit

Acceptable Variation Parameters:

• Resistance - Initial (Ri) and Resistance - Post Trip (R1): Minor variations acceptable within circuit design margins
• Time to Trip: Variations acceptable if circuit protection requirements are maintained
• Physical dimensions: Lead spacing and height must accommodate PCB layout constraints

The MF-RHT070-0 (Bourns Inc., Multifuse® series) is identified as a substitute part based on matching hold current (700 mA), trip current (1.4 A), operating temperature range (-40°C ~ 125°C), mounting type (Through Hole), and package configuration (Radial, Disc). However, the maximum voltage rating differs: MF-RHT070-0 is rated at 16V compared to RHEF070's 30V rating.

Parameter Comparison

Engineering Selection Recommendations

RHEF070 (Littelfuse PolySwitch®) is the primary specification component with active product status, comprehensive agency approvals (CSA, TUV, UL), and ROHS3 compliance. This part is suitable for circuits operating up to 30V with 700 mA hold current requirements.

MF-RHT070-0 (Bourns Inc. Multifuse®) is an active substitute part with ROHS3 compliance and AEC-Q200 automotive qualification. This part is suitable only for circuits operating at 16V or below. The differing lead spacing (0.114" versus 0.199") requires verification against PCB hole pattern specifications before implementation. The longer time-to-trip characteristic (4 s versus 3.2 s) must be evaluated against circuit protection timing requirements.

Selection between these parts depends on circuit voltage requirements: use RHEF070 for 16V < Vmax ≤ 30V applications; use MF-RHT070-0 only for Vmax ≤ 16V applications with compatible PCB layout.

Frequently Asked Questions (FAQ)

Q: Can MF-RHT070-0 be used as a direct replacement for RHEF070?

A: Not universally. MF-RHT070-0 is suitable only if the circuit operates at 16V or below. The RHEF070's 30V rating provides higher voltage capability. Additionally, the lead spacing differs (0.114" versus 0.199"), requiring PCB layout verification.

Q: What is the significance of the different time-to-trip values (3.2 s vs. 4 s)?

A: Time-to-trip defines the response delay before the fuse trips during an overcurrent event. RHEF070 responds faster (3.2 s) compared to MF-RHT070-0 (4 s). Circuit protection timing requirements must be evaluated to determine if the longer response time is acceptable.

Q: Are both parts RoHS compliant?

A: Yes. Both RHEF070 and MF-RHT070-0 are ROHS3 compliant and REACH unaffected.

Q: What does the lead spacing difference mean for PCB compatibility?

A: Lead spacing defines the distance between component leads. RHEF070 has 0.199" (5.05mm) spacing while MF-RHT070-0 has 0.114" (2.90mm) spacing. The PCB must have holes drilled at the correct spacing for the selected component. Verify your PCB layout before substitution.

Q: Does MF-RHT070-0 have the same agency approvals as RHEF070?

A: No. RHEF070 carries CSA, TUV, and UL approvals. MF-RHT070-0 approval agencies are not specified in the provided data. RHEF070 provides broader certification coverage for regulated applications.

Q: Can these parts be used interchangeably in automotive applications?

A: MF-RHT070-0 carries AEC-Q200 automotive qualification. RHEF070 automotive qualification status is not specified. For automotive applications, verify that the selected part meets your specific automotive standards and qualification requirements.