PS503R2 NTC Thermistor 50kΩ Equivalent & Substitute Parts

Part Overview

The PS503R2 is an NTC thermistor manufactured by Littelfuse Inc., featuring a 50kΩ resistance at 25°C in a bead epoxy package. This component is classified as obsolete, making equivalent substitutes necessary for ongoing applications and new designs. The PS503R2 operates within a maximum temperature range of 75°C and dissipates up to 30 mW, serving temperature sensing applications requiring stable thermal response characteristics.

Substiute Parts

PS503R2

Littelfuse Inc.In Stock: 892PS503R2 Datasheet

Current PartRFQ

ACW106

AmethermIn Stock: 1187ACW106 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for NTC thermistor beads is determined by the following parameters:

• Resistance value at 25°C (primary matching criterion)
• B-value characteristics (thermal response curve)
• Operating temperature range (must accommodate application requirements)
• Power dissipation rating (must meet or exceed application demands)
• Package configuration (bead type and lead wire dimensions)
• Regulatory compliance (RoHS, REACH, ECCN classifications)

The ACW106 qualifies as a substitute based on matching 50kΩ nominal resistance and compatible B-value range (B0/50: 4143K), while maintaining equivalent regulatory compliance and moisture sensitivity ratings.

Parameter Comparison

Engineering Selection Recommendations

The ACW106 serves as a direct substitute for the obsolete PS503R2 based on electrical parameter alignment and regulatory compliance. Both components maintain ROHS3 compliance and identical moisture sensitivity ratings (MSL 1). The ACW106 provides superior power dissipation capability (250 mW versus 30 mW), offering design margin for thermal applications. The operating temperature range of the ACW106 (0°C ~ 70°C) remains within the PS503R2 maximum specification of 75°C for most standard applications. Lead wire length differs by 0.50" (12.8mm), requiring mechanical layout verification in space-constrained installations.

Frequently Asked Questions (FAQ)

Q: Can the ACW106 directly replace the PS503R2 in existing designs? A: Yes, provided the operating temperature does not exceed 70°C and the mechanical lead wire length of 2.00" accommodates the circuit board layout. Electrical characteristics remain compatible within specified tolerances.

Q: What is the significance of the B-value difference between PS503R2 (4140K) and ACW106 (4143K)? A: The B-value defines the thermistor's thermal response curve. A 3K difference represents less than 0.1% variance and falls within acceptable substitution parameters for temperature sensing applications. Both components exhibit equivalent thermal characteristics across the operating range.

Q: Does the higher power dissipation rating of ACW106 (250 mW) affect circuit performance? A: No. Higher power dissipation rating indicates greater thermal capacity and does not alter electrical behavior. The component will operate identically to the PS503R2 in circuits designed for 30 mW or less.

Q: Are there packaging considerations when substituting to ACW106? A: The ACW106 is supplied in bulk packaging versus the PS503R2 specification. Both maintain identical bead epoxy construction. Lead wire length increases from 1.50" to 2.00", requiring verification of circuit board routing and component placement.

Q: What regulatory compliance applies to both components? A: Both PS503R2 and ACW106 maintain ROHS3 compliance, REACH unaffected status, and EAR99 ECCN classification, ensuring equivalent regulatory standing for commercial and industrial applications.