CTX33-4 Equivalent & Substitute Parts Reference

Part Overview

The CTX33-4 is an unshielded 2-coil inductor array manufactured by Eaton - Electronics Division in the OCTA-PAC® series. This surface mount component provides dual inductance configurations: 132.5 µH in series connection and 33.12 µH in parallel connection, with a maximum DC resistance of 72 mOhm in parallel mode and 287 mOhm in series mode.

The CTX33-4 carries an obsolete product status. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications utilizing this inductor array specification.

Substiute Parts

CTX33-4

Eaton - Electronics DivisionIn Stock: 1885CTX33-4 Datasheet

Current PartRFQ

CTX33-4-R

Eaton - Electronics DivisionIn Stock: 46603CTX33-4-R Datasheet

DirectRFQ

4448-122L

API Delevan Inc.In Stock: 8564448-122L Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CTX33-4 are identified based on strict electrical and mechanical parameter compatibility within the inductor array category. The substitution logic is organized into two groupings:

Direct Manufacturer Equivalent (CTX33-4-R): This part maintains identical electrical specifications across all critical parameters: 2-coil configuration, 33.12 µH parallel inductance, 132.5 µH series inductance, 72 mOhm maximum parallel DCR, 287 mOhm maximum series DCR, 1.8 A parallel current rating, and 900 mA series current rating. The tolerance remains ±20%. Physical dimensions and mounting characteristics are identical. The primary distinction is packaging format (Tape & Reel versus unspecified) and product status (Active versus Obsolete).

Similar Manufacturer Part (4448-122L): This API Delevan Inc. component provides functional equivalence with minor parameter variations within acceptable engineering tolerances. The inductance values differ slightly: 33 µH parallel (versus 33.12 µH) and 132 µH series (versus 132.5 µH), representing less than 1% deviation. The tolerance specification is tighter at ±15% (versus ±20%). DC resistance ratings remain identical at 72 mOhm parallel and 288 mOhm series (1 mOhm variance in series mode). Current ratings match exactly. Physical dimensions show minor variation: 0.530" x 0.530" (13.46 mm x 13.46 mm) versus 0.550" x 0.550" (13.97 mm x 13.97 mm), with height difference of 0.310" (7.87 mm) versus 0.250" (6.35 mm). Operating temperature range extends to -55°C to 125°C.

Key Parameters Determining Substitution Eligibility:

• Number of coils: 2
• Inductance values (parallel and series configurations)
• DC resistance specifications
• Current ratings
• Shielding type (unshielded)
• Surface mount configuration
• Nonstandard package classification

Parameter Comparison

Engineering Selection Recommendations

CTX33-4-R (Direct Manufacturer Equivalent): This part is the primary substitute for the obsolete CTX33-4. It maintains complete electrical and mechanical compatibility with identical specifications across all critical parameters. The CTX33-4-R carries Active product status with ROHS3 compliance, providing superior supply chain availability (46,518 pieces in stock versus 1,865 for the original part). The packaging format difference (Tape & Reel) is standard for active production components. Selection of CTX33-4-R is appropriate for new designs and ongoing production requiring direct replacement without circuit modification.

4448-122L (Similar Manufacturer Part): This API Delevan Inc. inductor array provides functional equivalence with minor parameter variations. The inductance deviation of less than 1% falls within typical circuit tolerance margins for most applications. The tighter tolerance specification (±15%) offers improved consistency. The extended operating temperature range (-55°C to 125°C) supports applications requiring broader thermal performance. Physical dimension differences require PCB layout verification to confirm fit within existing footprints. The MSL rating of 5A (24 Hours) indicates higher moisture sensitivity compared to the original part's MSL 1 rating, requiring appropriate handling procedures. Selection of 4448-122L is appropriate when supply constraints exist for CTX33-4-R or when extended temperature performance is required, provided PCB layout accommodates the dimensional variations.

Frequently Asked Questions (FAQ)

Q: Can CTX33-4-R be used as a direct replacement for CTX33-4 without circuit modification?

A: Yes. The CTX33-4-R maintains identical electrical specifications (inductance values, current ratings, DC resistance) and physical dimensions. No circuit modification is required. The primary difference is packaging format (Tape & Reel) and product status (Active). Both components are suitable for the same applications.

Q: What are the key differences between CTX33-4-R and 4448-122L?

A: The CTX33-4-R is a direct Eaton equivalent with identical specifications. The 4448-122L is a similar part from API Delevan with minor variations: inductance values differ by less than 1% (33 µH vs 33.12 µH parallel; 132 µH vs 132.5 µH series), tolerance is tighter (±15% vs ±20%), operating temperature range is extended (-55°C to 125°C vs -40°C to 85°C), and physical dimensions vary slightly (0.530" x 0.530" x 0.310" vs 0.550" x 0.550" x 0.250"). The 4448-122L has higher moisture sensitivity (MSL 5A vs MSL 1).

Q: Are there PCB layout considerations when substituting with 4448-122L?

A: Yes. The 4448-122L has different physical dimensions: footprint is 0.530" x 0.530" (versus 0.550" x 0.550") and height is 0.310" (versus 0.250"). PCB layout must be verified to confirm the component fits within the existing footprint and clearance space. The smaller footprint may provide layout benefits, but height difference requires clearance verification.

Q: What is the significance of the MSL rating difference between these parts?

A: The CTX33-4 and CTX33-4-R have MSL 1 (Unlimited), meaning they can be stored indefinitely without moisture absorption concerns. The 4448-122L has MSL 5A (24 Hours), indicating it must be used within 24 hours of package opening or stored in controlled humidity conditions. This affects handling procedures and inventory management but does not impact electrical performance once soldered.

Q: Which substitute part should be selected for new designs?

A: CTX33-4-R is the recommended choice for new designs. It provides complete electrical and mechanical compatibility with the original CTX33-4, carries Active product status ensuring long-term availability, and meets ROHS3 compliance requirements. The 4448-122L is an alternative when CTX33-4-R supply is constrained or when extended temperature performance is required, provided PCB layout accommodates dimensional variations.

Q: Are all three parts suitable for the same current and inductance requirements?

A: Yes, for practical applications. All three parts support 1.8 A parallel current rating and 900 mA series current rating. Inductance values are equivalent within engineering tolerances: CTX33-4 and CTX33-4-R are identical at 33.12 µH parallel and 132.5 µH series; 4448-122L differs by less than 1% at 33 µH parallel and 132 µH series. These variations are negligible for most circuit applications.