40F75R Equivalent & Substitute Parts

Part Overview

The Ohmite 40F75R is a 75 Ohm, 1% tolerance, 10W axial wirewound through-hole resistor from the Ohmicone® 40 series. This component is designed for applications requiring high precision and power dissipation in compact form factors. The part maintains active product status with 1188 units in current inventory. Substitute parts are identified when equivalent electrical performance can be achieved within the allowable parameter tolerances for this resistor category, particularly when original stock availability or specific compliance requirements necessitate alternative sourcing.

Substiute Parts

40F75R

OhmiteIn Stock: 121240F75R Datasheet

Current PartRFQ

20J75RE

OhmiteIn Stock: 161520J75RE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 40F75R is determined by the following critical parameters:

• Resistance Value: Must be 75 Ohms
• Power Rating: Must be 10W minimum
• Package Type: Must be Axial configuration
• Composition: Must be Wirewound
• Number of Terminations: Must be 2

The 20J75RE qualifies as a substitute because it maintains the same resistance value (75 Ohms), power rating (10W), axial package configuration, wirewound composition, and two-terminal design. While tolerance and temperature coefficient specifications differ, these variations remain within acceptable substitution parameters for this resistor category.

Parameter Comparison

Engineering Selection Recommendations

Both the 40F75R and 20J75RE maintain active product status from Ohmite. The primary distinction lies in compliance posture: the 40F75R is RoHS non-compliant, while the 20J75RE achieves ROHS3 compliance. Selection between these parts should be driven by regulatory requirements applicable to the end application. The 20J75RE additionally incorporates flame retardant coating and safety features in its construction. Tolerance specification differences (±1% versus ±5%) and temperature coefficient variations (±20ppm/°C versus ±30ppm/°C) must be evaluated against circuit-level precision requirements.

Frequently Asked Questions (FAQ)

Q: Can the 20J75RE directly replace the 40F75R in existing designs?

A: Both parts share identical resistance value (75 Ohms), power rating (10W), axial package configuration, and wirewound composition. Physical dimensions are comparable (within 0.012" diameter and 0.044" length). Substitution is mechanically and electrically feasible. Tolerance and temperature coefficient differences require circuit-level validation.

Q: What are the tolerance implications of substituting 40F75R with 20J75RE?

A: The 40F75R specifies ±1% tolerance, while the 20J75RE specifies ±5% tolerance. In applications where resistance value precision is critical, this four-percentage-point difference may impact circuit performance. Verify tolerance requirements before substitution.

Q: How do temperature coefficients affect substitution suitability?

A: The 40F75R exhibits ±20ppm/°C temperature coefficient; the 20J75RE exhibits ±30ppm/°C. In temperature-sensitive applications, the higher coefficient of the substitute part may introduce greater resistance drift across operating temperature ranges. Thermal performance analysis is recommended for precision circuits.

Q: Are there compliance considerations for substitution?

A: The 40F75R is RoHS non-compliant, while the 20J75RE is ROHS3 compliant. Applications subject to RoHS directives or customer compliance mandates may require the 20J75RE. Verify regulatory requirements for your end application.

Q: Do physical dimension differences affect PCB layout compatibility?

A: The 40F75R measures 0.406" diameter × 1.902" length; the 20J75RE measures 0.394" diameter × 1.858" length. Both are axial packages with two terminations. Dimensional differences are minor and typically accommodate standard through-hole PCB layouts designed for axial resistors.