45F12RE Equivalent & Substitute Parts

Part Overview

The 45F12RE is a 12 Ohms ±1% 5W through-hole resistor manufactured by Ohmite, part of the Ohmicone® 40 series. This axial wirewound resistor is designed for applications requiring precision resistance with high power dissipation capability. The part is currently active in production with full RoHS compliance and unlimited moisture sensitivity rating. Substitute parts are identified when original stock is unavailable or when design requirements permit alternative manufacturers meeting identical electrical and mechanical specifications.

Substiute Parts

45F12RE

OhmiteIn Stock: 113645F12RE Datasheet

Current PartRFQ

UB5C-12RF1

RiedonIn Stock: 1469UB5C-12RF1 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 45F12RE are qualified based on the following critical parameters that must match or exceed the main part specifications:

• Resistance value: 12 Ohms (exact match required)
• Tolerance: ±1% (exact match required)
• Power rating: 5W (exact match required)
• Composition: Wirewound (exact match required)
• Package type: Axial (exact match required)
• Temperature coefficient: ±20ppm/°C (exact match required)
• RoHS compliance: Required
• Moisture sensitivity: MSL 1 or better

The UB5C-12RF1 manufactured by Riedon meets all critical electrical parameters and packaging requirements. Both parts are active products with current production status and full regulatory compliance.

Parameter Comparison

Engineering Selection Recommendations

The UB5C-12RF1 is electrically equivalent to the 45F12RE across all critical parameters: resistance value, tolerance, power rating, temperature coefficient, and composition. Both parts carry active product status and full RoHS compliance, meeting current regulatory requirements.

The primary consideration for substitution is physical dimension difference. The UB5C-12RF1 has a smaller form factor (0.250" diameter × 0.500" length) compared to the 45F12RE (0.343" diameter × 0.937" length). This dimensional variance may affect PCB layout, mechanical clearance, and thermal management characteristics in the application. The operating temperature range of the UB5C-12RF1 extends to 250°C versus 275°C for the 45F12RE, which is acceptable for most industrial applications but should be verified against specific circuit requirements.

Both parts are suitable for direct electrical substitution when physical space and thermal requirements permit the dimensional differences.

Frequently Asked Questions (FAQ)

Q: Can the UB5C-12RF1 replace the 45F12RE in all applications?

A: Electrical substitution is valid based on matching resistance, tolerance, power rating, and temperature coefficient. Physical dimensions differ significantly, so PCB layout compatibility and mechanical clearance must be confirmed before implementation.

Q: What is the significance of the different physical dimensions?

A: The UB5C-12RF1 is substantially smaller in both diameter and length. This affects board space requirements, lead routing, and thermal dissipation characteristics. Applications with tight spatial constraints or specific thermal management designs may require layout modification.

Q: Are both parts RoHS compliant?

A: Yes. The 45F12RE is RoHS Compliant, and the UB5C-12RF1 is ROHS3 Compliant. Both meet current environmental and regulatory standards.

Q: Does the operating temperature difference matter?

A: The UB5C-12RF1 operates to 250°C versus 275°C for the 45F12RE. For applications operating below 250°C, this difference is not a limiting factor. Applications requiring operation above 250°C must use the 45F12RE.

Q: Are the moisture sensitivity ratings equivalent?

A: Yes. Both parts carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions for storage or handling.

Q: What additional features does the UB5C-12RF1 provide?

A: The UB5C-12RF1 includes current sense, flame proof, moisture resistant, pulse withstanding, and safety certifications as standard features. These do not affect basic substitution compatibility but may provide additional design benefits.