45F27R Equivalent & Substitute Parts

Part Overview

The Ohmite 45F27R is a 27 Ohm, 1% tolerance, 5W axial wirewound through-hole resistor from the Ohmicone® 40 series. This component is currently active in production with 1016 units in stock. Axial wirewound resistors of this specification are used in power applications requiring precise resistance values and high power dissipation capabilities. Substitute parts may be required due to supply chain constraints, regional availability, or specific application requirements for enhanced features such as moisture resistance or improved compliance certifications.

Substiute Parts

45F27R

OhmiteIn Stock: 110245F27R Datasheet

Current PartRFQ

ALSR0527R00FE12

Vishay DaleIn Stock: 1191ALSR0527R00FE12 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 45F27R is determined by the following critical parameters:

• Resistance Value: Must be 27 Ohms
• Tolerance: Must be ±1% or tighter
• Power Rating: Must be 5W or greater
• Composition: Must be Wirewound
• Package Type: Must be Axial with 2 terminations
• Form Factor: Physical dimensions must be compatible with axial through-hole mounting

The Vishay Dale ALSR0527R00FE12 meets all mandatory substitution criteria. While it exhibits a slightly higher temperature coefficient (±30ppm/°C versus ±20ppm/°C) and includes moisture-resistant features not present in the 45F27R, these represent enhancements rather than deviations from core electrical specifications.

Parameter Comparison

Engineering Selection Recommendations

45F27R (Ohmite): Select this part for applications where the original specification is required and supply is available. This component is active in production with adequate inventory.

ALSR0527R00FE12 (Vishay Dale): This substitute is electrically equivalent and offers additional advantages including ROHS3 compliance, moisture resistance, and a defined operating temperature range of -65°C to 250°C. The slightly larger temperature coefficient (±30ppm/°C) remains within acceptable tolerances for most applications requiring ±1% precision. Physical dimensions are slightly smaller, which may provide layout advantages in space-constrained designs. This part is suitable for applications requiring enhanced environmental protection or regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can the ALSR0527R00FE12 be used as a direct replacement for the 45F27R?

A: Yes. Both components share identical resistance (27 Ohms), tolerance (±1%), power rating (5W), composition (wirewound), and axial package configuration. The ALSR0527R00FE12 is electrically and mechanically compatible for through-hole mounting applications.

Q: What is the significance of the temperature coefficient difference?

A: The 45F27R has a temperature coefficient of ±20ppm/°C while the ALSR0527R00FE12 has ±30ppm/°C. For a 27 Ohm resistor, this difference results in a maximum resistance change of approximately 0.054 Ohms across a 100°C temperature swing for the 45F27R and 0.081 Ohms for the substitute. Both remain within ±1% tolerance across typical operating ranges.

Q: Are there physical installation differences?

A: The ALSR0527R00FE12 is slightly smaller (0.312" diameter versus 0.343" diameter; 0.875" length versus 0.937" length). Both are axial through-hole components with 2 terminations and are compatible with standard PCB mounting. The smaller form factor may provide layout benefits.

Q: What does ROHS3 compliance mean for the ALSR0527R00FE12?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances Directive requirements, restricting the use of specific hazardous materials. The 45F27R is listed as RoHS non-compliant. Applications subject to RoHS regulations should use the ALSR0527R00FE12.

Q: Does moisture resistance affect electrical performance?

A: The moisture-resistant feature of the ALSR0527R00FE12 enhances reliability in humid or wet environments but does not alter the core electrical specifications. Resistance value, tolerance, and power rating remain identical to the 45F27R.