Equivalent & Substitute Parts for Ohmite 45F20K

Part Overview

The Ohmite 45F20K is a 20 kOhms ±1% 5W through-hole resistor with axial wirewound construction, part of the Ohmicone® 40 series. This component is classified as Active product status and remains in production. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and supply chain continuity when the primary part number becomes unavailable or when alternative packaging or compliance requirements necessitate component substitution.

Substiute Parts

45F20K

OhmiteIn Stock: 90145F20K Datasheet

Current PartRFQ

45F20KE

OhmiteIn Stock: 128245F20KE Datasheet

DirectRFQ

ALSR0520K00FE12

Vishay DaleIn Stock: 1536ALSR0520K00FE12 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 45F20K is determined by the following critical parameters: resistance value (20 kOhms), tolerance (±1%), power rating (5W), composition (wirewound), and package configuration (axial with 2 terminations). All identified substitute parts meet these core electrical and mechanical specifications. The substitute parts listed—45F20KE and ALSR0520K00FE12—maintain functional equivalence across these parameters while differing in packaging format, RoHS compliance status, temperature coefficient range, and operating temperature specifications.

Parameter Comparison

Engineering Selection Recommendations

The 45F20KE represents a direct manufacturer equivalent from Ohmite with identical electrical specifications and physical dimensions. This part is ROHS3 compliant, addressing regulatory requirements where the primary 45F20K does not meet RoHS standards. The 45F20KE is suitable for applications requiring Ohmite component continuity with enhanced environmental compliance.

The ALSR0520K00FE12 from Vishay Dale provides cross-manufacturer substitution with equivalent electrical performance. This part features ROHS3 compliance, moisture-resistant construction, and a specified operating temperature range of -65°C to 250°C. Physical dimensions are slightly reduced (0.312" diameter versus 0.343"), and temperature coefficient is ±30ppm/°C compared to ±20ppm/°C for the primary part. The ALSR0520K00FE12 is suitable for applications requiring extended temperature operation and moisture resistance where dimensional constraints permit the smaller form factor.

Frequently Asked Questions (FAQ)

Q: Can the 45F20KE be used as a direct replacement for the 45F20K?

A: Yes. The 45F20KE maintains identical resistance (20 kOhms), tolerance (±1%), power rating (5W), temperature coefficient (±20ppm/°C), and physical dimensions (0.343" Dia x 0.937" L). The primary difference is RoHS3 compliance status. Substitution is electrically and mechanically equivalent.

Q: What are the key differences between the 45F20K and ALSR0520K00FE12?

A: Both parts share identical resistance, tolerance, and power rating specifications. The ALSR0520K00FE12 differs in: temperature coefficient (±30ppm/°C versus ±20ppm/°C), specified operating temperature range (-65°C to 250°C versus unspecified), physical dimensions (0.312" Dia x 0.875" L versus 0.343" Dia x 0.937" L), and moisture resistance features. The Vishay Dale part is ROHS3 compliant and suitable for extended temperature applications.

Q: Are there dimensional compatibility concerns when substituting the ALSR0520K00FE12?

A: The ALSR0520K00FE12 has a smaller diameter (0.312" versus 0.343") and shorter length (0.875" versus 0.937"). PCB layout and mechanical clearance must be verified before substitution. The reduced form factor may provide advantages in space-constrained designs.

Q: Which substitute part should be selected for RoHS-compliant applications?

A: Both 45F20KE and ALSR0520K00FE12 are ROHS3 compliant. The 45F20KE maintains Ohmite manufacturer continuity with identical specifications. The ALSR0520K00FE12 provides cross-manufacturer options with additional moisture resistance and extended temperature range.

Q: What is the significance of the moisture-resistant feature on the ALSR0520K00FE12?

A: The ALSR0520K00FE12 is specified as moisture-resistant with Moisture Sensitivity Level 1 (Unlimited). This designation indicates enhanced protection against moisture ingress and is relevant for applications exposed to humid environments or requiring extended shelf life without controlled storage conditions.