DC503J2K NTC Thermistor 50kΩ Equivalent & Substitute Parts

Part Overview

The DC503J2K is an NTC thermistor manufactured by Littelfuse Inc., designed as a 50kΩ bead-type temperature sensor with epoxy packaging. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The part operates across a temperature range up to 150°C and is suitable for applications requiring precision temperature measurement and thermal compensation in electronic circuits.

Substiute Parts

DC503J2K

Littelfuse Inc.In Stock: 1172DC503J2K Datasheet

Current PartRFQ

B57861S0503J040

EPCOS - TDK ElectronicsIn Stock: 881B57861S0503J040 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DC503J2K is determined by the following critical parameters:

• Nominal Resistance: 50kΩ at 25°C (primary selection criterion)
• Package Configuration: Bead form factor with free-hanging leads
• Temperature Operating Range: Minimum capability to -55°C and maximum to 155°C
• Thermal Characteristics: B-value parameters defining the thermistor's temperature coefficient
• Regulatory Compliance: RoHS3 compliance and ECCN classification (EAR99)

The B57861S0503J040 from EPCOS - TDK Electronics meets these substitution criteria with compatible electrical characteristics and enhanced specifications including tighter tolerance and active product status.

Parameter Comparison

Engineering Selection Recommendations

The B57861S0503J040 is a direct functional substitute for the obsolete DC503J2K based on the following engineering criteria:

• Electrical Equivalence: Both components maintain 50kΩ nominal resistance at 25°C with compatible thermal response characteristics
• Mechanical Compatibility: Identical bead package configuration and free-hanging lead mounting enable direct circuit board replacement
• Regulatory Alignment: Both components satisfy ROHS3 compliance and EAR99 export classification requirements
• Active Manufacturing Status: The B57861S0503J040 is currently in active production, ensuring long-term availability and supply chain continuity
• Enhanced Specifications: The substitute provides superior tolerance specifications (±5% resistance, ±1% B-value) compared to the original part, improving circuit performance and reliability

Frequently Asked Questions (FAQ)

Q: Can the B57861S0503J040 be used as a direct replacement for DC503J2K in existing designs?

A: Yes. Both components share identical 50kΩ nominal resistance, bead package configuration, and free-hanging mounting type. The substitute's tighter tolerance specifications and extended temperature range provide equivalent or improved performance in the same circuit application.

Q: What is the primary reason for substitution?

A: The DC503J2K is classified as obsolete. The B57861S0503J040 provides an active, currently manufactured alternative with compatible electrical and mechanical specifications.

Q: Are there differences in thermal characteristics between these parts?

A: Both components function as NTC thermistors with similar thermal response. The B57861S0503J040 specifies a B25/100 value of 3760K compared to the DC503J2K's B0/50 value of 3892K. These represent different measurement reference points and both are suitable for temperature sensing applications within their respective operating ranges.

Q: Do both parts meet the same regulatory requirements?

A: Yes. Both the DC503J2K and B57861S0503J040 are ROHS3 compliant and classified as EAR99 for export purposes, meeting identical regulatory standards.

Q: What is the packaging difference between these components?

A: The DC503J2K specifies epoxy bead packaging, while the B57861S0503J040 specifies standard bead packaging. Both maintain the same functional form factor and free-hanging lead configuration suitable for circuit board integration.