45F12K5 Equivalent & Substitute Parts

Part Overview

The 45F12K5 is a 12.5 kOhms ±1% 5W through-hole resistor manufactured by Ohmite in the Ohmicone® 40 series. This axial wirewound resistor is designed for applications requiring precision resistance values with moderate power dissipation in a compact form factor. The part maintains active product status and is available in inventory. Substitute parts are identified to provide alternative sourcing options when the primary manufacturer part is unavailable or when design requirements permit equivalent electrical and mechanical specifications.

Substiute Parts

45F12K5

OhmiteIn Stock: 71045F12K5 Datasheet

Current PartRFQ

ALSR0512K50FE12

Vishay DaleIn Stock: 1458ALSR0512K50FE12 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 45F12K5 is determined by the following critical parameters:

• Resistance Value: Must be 12.5 kOhms
• Tolerance: Must be ±1% or tighter
• Power Rating: Must be 5W or greater
• Composition: Wirewound construction required
• Package: Axial through-hole configuration required
• Terminations: Two-terminal configuration required

The substitute part ALSR0512K50FE12 (Vishay Dale) meets all mandatory electrical and mechanical criteria. While dimensional variations exist within acceptable tolerances for through-hole axial components, both parts maintain compatible footprint characteristics for standard PCB applications.

Parameter Comparison

Engineering Selection Recommendations

45F12K5 (Ohmite): Select this part when the original design specification requires the Ohmicone® 40 series characteristics or when RoHS non-compliant status is acceptable for the application. This part is active and in stock.

ALSR0512K50FE12 (Vishay Dale): Select this substitute when RoHS3 compliance is required or when the broader operating temperature range (-65°C ~ 250°C) is necessary for the application. The ALSR series provides moisture-resistant construction and is available in higher inventory quantities. The slightly lower temperature coefficient (±30ppm/°C versus ±20ppm/°C) and smaller physical dimensions may be advantageous in space-constrained designs.

Both parts are active products with established supply chains and are suitable for direct substitution in applications where the specified electrical parameters are met.

Frequently Asked Questions (FAQ)

Q: Can ALSR0512K50FE12 be used as a direct replacement for 45F12K5?

A: Yes. Both parts share identical resistance (12.5 kOhms), tolerance (±1%), power rating (5W), composition (wirewound), and package type (axial). The ALSR0512K50FE12 has slightly different physical dimensions and a broader operating temperature range, but both are compatible with standard through-hole PCB layouts.

Q: What is the difference in temperature coefficient between these parts?

A: The 45F12K5 has a temperature coefficient of ±20ppm/°C, while the ALSR0512K50FE12 has ±30ppm/°C. For most general-purpose applications, this difference is negligible. Applications requiring tighter temperature stability should specify the 45F12K5.

Q: Does the ALSR0512K50FE12 have any compliance advantages?

A: Yes. The ALSR0512K50FE12 is ROHS3 compliant, whereas the 45F12K5 is RoHS non-compliant. If your application or region requires RoHS compliance, the ALSR0512K50FE12 is the appropriate choice.

Q: Are the physical dimensions compatible with existing PCB layouts?

A: Both parts are axial through-hole resistors with similar form factors. The 45F12K5 measures 0.343" Dia x 0.937" L, while the ALSR0512K50FE12 measures 0.312" Dia x 0.875" L. These minor dimensional differences are within acceptable tolerances for standard through-hole component placement and should not require PCB redesign.

Q: What is the moisture resistance feature on the ALSR0512K50FE12?

A: The ALSR series includes moisture-resistant construction, which provides enhanced protection in humid or corrosive environments. The Moisture Sensitivity Level (MSL) rating of 1 (Unlimited) indicates no moisture sensitivity restrictions during storage or handling.