PX222J2 Equivalent & Substitute Parts

Part Overview

The PX222J2 is an NTC thermistor bead manufactured by Littelfuse Inc., designed for temperature sensing applications. It features a resistance of 2.252kΩ at 25°C with a B value of 3892K and operates up to 120°C with a maximum power dissipation of 30mW. The part is currently obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and component procurement.

Substiute Parts

PX222J2

Littelfuse Inc.In Stock: 723PX222J2 Datasheet

Current PartRFQ

701033

TE Connectivity Measurement SpecialtiesIn Stock: 1135701033 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The TE Connectivity Measurement Specialties part 701033 qualifies as a manufacturer-recommended substitute based on the following critical parameters:

• Identical resistance value at 25°C: 2.252kΩ
• B value match within engineering tolerance: 3891K (substitute) versus 3892K (original), representing a 0.03% variance
• Compatible package configuration: Bead form factor with free hanging mounting
• Equivalent RoHS3 compliance and REACH unaffected status
• Extended operating temperature range: -55°C to 150°C (exceeds original 120°C maximum)
• Active product status with current manufacturing availability

The primary design consideration for substitution is the thermal response characteristic defined by the B value and resistance combination. The 701033 maintains functional equivalence within standard thermistor tolerance specifications.

Parameter Comparison

Engineering Selection Recommendations

The 701033 is the manufacturer-recommended substitute for the obsolete PX222J2. Selection of this alternative is supported by:

• Identical electrical characteristics (2.252kΩ resistance, 3891K B value)
• Active product status ensuring long-term availability and supply chain continuity
• Equivalent regulatory compliance (ROHS3, REACH unaffected)
• Improved resistance tolerance specification (±0.1°C versus ±1°C)
• Extended operating temperature capability (-55°C to 150°C)

The primary design consideration is the lead wire length difference: the substitute provides 3.00" (76.20mm) versus the original 1.50" (38.00mm). This difference must be evaluated within the specific application's physical layout and thermal coupling requirements.

Frequently Asked Questions (FAQ)

Q: Can the 701033 directly replace the PX222J2 in all applications?

A: The 701033 provides electrical equivalence based on resistance and B value specifications. The extended lead wire length (3.00" versus 1.50") requires physical layout verification to ensure proper thermal coupling and mechanical fit within the application.

Q: What is the significance of the B value difference (3891K versus 3892K)?

A: The B value defines the thermistor's temperature-resistance relationship. The 0.03% variance between parts falls within standard thermistor manufacturing tolerances and does not create functional incompatibility for temperature sensing applications.

Q: Why is the resistance tolerance specification different?

A: The 701033 offers tighter tolerance (±0.1°C) compared to the original (±1°C). This represents an improvement in component precision and does not prevent substitution.

Q: Are there compliance concerns with using the substitute?

A: Both parts maintain ROHS3 compliance and REACH unaffected status. No regulatory barriers exist for substitution.

Q: Does the longer lead wire affect thermal response?

A: Lead wire length influences thermal coupling to the measurement environment. Applications requiring specific thermal time constants should evaluate whether the extended lead length (76.20mm versus 38.00mm) affects measurement accuracy or response time.