WW3JB390R Equivalent & Substitute Parts

Part Overview

The WW3JB390R is a 390 Ohms ±5% 3W axial wirewound resistor manufactured by Stackpole Electronics Inc. This through-hole component features moisture-resistant construction and operates across a wide temperature range from -55°C to 350°C. The part is currently active in production with ROHS3 compliance. Equivalent and substitute parts are identified when design requirements permit tolerance relaxation, packaging format changes, or when primary inventory availability necessitates alternative sourcing.

Substiute Parts

WW3JB390R

Stackpole Electronics IncIn Stock: 905WW3JB390R Datasheet

Current PartRFQ

WW3FT390R

Stackpole Electronics IncIn Stock: 2853WW3FT390R Datasheet

UpgradeRFQ

43J390E

OhmiteIn Stock: 103343J390E Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the WW3JB390R is determined by the following criteria:

Primary Matching Parameters:

• Resistance value: 390 Ohms (exact match required)
• Power rating: 3W (exact match required)
• Composition: Wirewound (exact match required)
• Package type: Axial (exact match required)
• Temperature coefficient: ±20ppm/°C (exact match required)
• Operating temperature range: -55°C to 350°C (exact match or better required)
• RoHS compliance: ROHS3 Compliant (exact match required)

Allowable Variations:

• Tolerance: May be tighter (lower percentage) than ±5%
• Packaging format: May differ (Bulk to Cut Tape or equivalent)
• Physical dimensions: Minor variations acceptable within industry standards for axial wirewound resistors
• Manufacturer: Different manufacturers acceptable if all electrical and mechanical parameters align

Two substitute parts meet these criteria and are listed below.

Parameter Comparison

Engineering Selection Recommendations

WW3FT390R (Stackpole Electronics Inc): This substitute offers improved tolerance specification at ±1% compared to the ±5% of the main part, while maintaining identical electrical and thermal characteristics. Both parts are manufactured by Stackpole Electronics Inc and share the same series designation. The primary difference is packaging format (Cut Tape versus Bulk) and tighter tolerance. This part is suitable for applications where improved accuracy is beneficial or where Cut Tape packaging is preferred for automated assembly processes.

43J390E (Ohmite): This manufacturer-recommended substitute is from the Ohmicone® 40 series and matches all critical electrical parameters including resistance, power rating, tolerance, and temperature coefficient. Physical dimensions differ slightly (0.220" Dia x 0.594" L versus 0.187" Dia x 0.560" L), which is within acceptable variation for axial wirewound resistors. Both parts maintain ROHS3 compliance and active production status. This part is suitable for applications where Ohmite component qualification is required or where inventory sourcing from an alternative manufacturer is necessary.

Frequently Asked Questions (FAQ)

Q: Can WW3FT390R be used as a direct replacement for WW3JB390R?

A: Yes. WW3FT390R is electrically and mechanically compatible. The ±1% tolerance is tighter than the ±5% specification of WW3JB390R, making it suitable for any application requiring the original part. The primary difference is packaging format (Cut Tape versus Bulk).

Q: What is the significance of the tolerance difference between WW3JB390R (±5%) and WW3FT390R (±1%)?

A: Tolerance defines the allowable resistance variation from the nominal 390 Ohm value. WW3JB390R allows variation between 370.5 and 409.5 Ohms, while WW3FT390R allows variation between 386.1 and 393.9 Ohms. Applications requiring tighter resistance control benefit from WW3FT390R; applications with ±5% tolerance requirements are satisfied by either part.

Q: Are there physical dimension differences between these parts?

A: Yes. WW3JB390R and WW3FT390R share identical dimensions (0.187" Dia x 0.560" L). The 43J390E has slightly larger dimensions (0.220" Dia x 0.594" L). Both dimension sets are standard for 3W axial wirewound resistors and are compatible with typical through-hole PCB layouts.

Q: Do all three parts meet the same compliance requirements?

A: Yes. All three parts are ROHS3 compliant, REACH unaffected, and classified as EAR99 for export control purposes. All maintain active production status.

Q: Which substitute should be selected for new designs?

A: Selection depends on specific design requirements. For improved tolerance performance, select WW3FT390R. For alternative manufacturer sourcing or Ohmite component qualification, select 43J390E. Both are fully compatible with applications originally specified for WW3JB390R.