UB3C-300RF8 Equivalent & Substitute Parts

Part Overview

The UB3C-300RF8 is a 300 Ohm ±1% 3W axial wirewound resistor manufactured by Riedon. This through-hole component is designed for current sense applications and features flame proof, moisture resistant, pulse withstanding, and safety certifications. The part is currently active in production with 872 pieces in stock. Equivalent and substitute parts are identified when component availability is limited, supply chain disruptions occur, or design flexibility permits alternative sourcing while maintaining electrical and mechanical compatibility.

Substiute Parts

UB3C-300RF8

RiedonIn Stock: 928UB3C-300RF8 Datasheet

Current PartRFQ

43F300E

OhmiteIn Stock: 95943F300E Datasheet

MFR RecommendedRFQ

WW3FT300R

Stackpole Electronics IncIn Stock: 2575WW3FT300R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the UB3C-300RF8 are qualified based on the following electrical and mechanical parameters:

• Resistance value: 300 Ohms
• Tolerance: ±1%
• Power rating: 3W
• Composition: Wirewound
• Package: Axial through-hole
• Temperature coefficient: ±20ppm/°C
• RoHS compliance: ROHS3 Compliant
• Termination count: 2

The identified substitutes (43F300E and WW3FT300R) meet all core electrical specifications and maintain axial package compatibility. Physical dimensions vary within acceptable limits for standard PCB mounting applications. All substitutes are active products with confirmed inventory availability.

Parameter Comparison

Engineering Selection Recommendations

All three parts (UB3C-300RF8, 43F300E, and WW3FT300R) are active products with ROHS3 compliance and meet the core electrical specifications of 300 Ohms ±1% at 3W with wirewound composition and axial package configuration.

The UB3C-300RF8 offers the smallest physical footprint (4.00mm diameter x 8.90mm length) and includes current sense, flame proof, moisture resistant, and pulse withstanding features. This part is suitable for space-constrained applications requiring enhanced safety certifications.

The 43F300E (Ohmite Ohmicone® 40 series) provides a bulk packaging option with equivalent electrical performance. Physical dimensions are larger (5.60mm diameter x 15.10mm length), which may require PCB layout adjustment.

The WW3FT300R (Stackpole WW series) offers the highest inventory availability (2473 pieces) and extended operating temperature range (-55°C ~ 350°C). Physical dimensions (4.75mm diameter x 14.22mm length) fall between the other two options. This part includes moisture resistant features and is supplied in cut tape format.

Selection should be based on PCB layout constraints, packaging format requirements, and application-specific temperature operating conditions.

Frequently Asked Questions (FAQ)

Q: Can the 43F300E replace the UB3C-300RF8 in all applications?

A: The 43F300E meets all core electrical specifications (300 Ohms ±1%, 3W, wirewound, axial package). However, physical dimensions differ (5.60mm diameter x 15.10mm length versus 4.00mm diameter x 8.90mm length). PCB layout verification is required to confirm mounting compatibility. The 43F300E does not specify operating temperature range, while the UB3C-300RF8 operates to 250°C.

Q: What are the key differences between the WW3FT300R and UB3C-300RF8?

A: Both parts share identical electrical specifications (300 Ohms ±1%, 3W, ±20ppm/°C). The WW3FT300R has an extended operating temperature range (-55°C ~ 350°C versus -55°C ~ 250°C) and includes moisture resistant features. Physical dimensions differ: WW3FT300R is 4.75mm diameter x 14.22mm length. The WW3FT300R is supplied in cut tape format with significantly higher inventory (2473 pieces).

Q: Are all three parts RoHS compliant?

A: Yes, all three parts (UB3C-300RF8, 43F300E, and WW3FT300R) are ROHS3 compliant.

Q: How do physical dimensions affect substitution?

A: Axial resistors mount through PCB holes with lead spacing determined by body length. The UB3C-300RF8 (8.90mm length) has the shortest lead span, while the 43F300E (15.10mm length) has the longest. PCB hole spacing and component density must be verified before substitution to ensure proper fit and assembly compatibility.

Q: Which substitute offers the best inventory availability?

A: The WW3FT300R (Stackpole) offers the highest inventory with 2473 pieces in stock, compared to 872 pieces for the UB3C-300RF8 and 886 pieces for the 43F300E.

Q: Do all parts support current sense applications?

A: The UB3C-300RF8 is specifically designated for current sense applications. The 43F300E and WW3FT300R are general-purpose wirewound resistors without explicit current sense designation, though they meet the electrical requirements for such use.