ERT-D2FFL251S NTC Thermistor Equivalent & Substitute Parts

Part Overview

The ERT-D2FFL251S is an NTC thermistor manufactured by Panasonic Electronic Components, rated at 250 ohms resistance at 25°C with a B25/50 value of 3500K. This component is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support, production continuity, and component sourcing.

The thermistor is designed for temperature sensing applications requiring through-hole mounting in a 5mm disc package format. With an operating temperature range of -30°C to 60°C and maximum power rating of 400 mW, this component serves applications in consumer electronics, industrial controls, and thermal management systems.

Substiute Parts

ERT-D2FFL251S

Panasonic Electronic ComponentsIn Stock: 769ERT-D2FFL251S Datasheet

Current PartRFQ

AL03006-165.9-55-G1

Amphenol ThermometricsIn Stock: 1987AL03006-165.9-55-G1 Datasheet

SimilarRFQ

MF11-0025005

CanthermIn Stock: 1157MF11-0025005 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for NTC thermistors is determined by the following critical parameters:

1. Resistance Value @ 25°C: Must match at 250 ohms
2. Thermal Characteristics: B-value parameters determine temperature response curve; B25/50 or B25/85 values must be within acceptable application tolerance
3. Operating Temperature Range: Substitute must encompass or exceed the original operating window
4. Mounting Configuration: Through-hole mounting is required; package geometry must be compatible with PCB layout
5. Power Dissipation: Maximum power rating must meet or exceed application requirements
6. Tolerance Specifications: Resistance and B-value tolerances affect circuit accuracy

The two identified substitutes—AL03006-165.9-55-G1 and MF11-0025005—both meet the core electrical requirements of 250 ohms resistance at 25°C and through-hole mounting. However, they differ in package geometry, thermal characteristics, and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

AL03006-165.9-55-G1 (Amphenol Thermometrics)

This substitute provides active product status with RoHS compliance certification. The resistance tolerance of ±10% is tighter than the original ±15%, improving circuit accuracy. The operating temperature range of -50°C to 150°C significantly exceeds the original specification, providing design margin for thermal extremes. However, the package geometry differs substantially—this component uses DO-204AH/DO-35 axial configuration rather than disc format, requiring PCB layout modification. The B25/85 value of 2983K differs from the original B25/50 of 3500K, indicating a different thermal response curve that must be evaluated against application requirements.

MF11-0025005 (Cantherm)

This substitute offers active product status with ROHS3 compliance and REACH unaffected designation. The resistance tolerance of ±5% provides superior accuracy compared to the original ±15%. The B25/50 value of 3600K closely matches the original 3500K specification, ensuring similar thermal response characteristics. Maximum power dissipation of 500 mW exceeds the original 400 mW rating. The operating temperature range of -55°C to 125°C provides adequate margin. The disc package format (6.5mm diameter x 5.0mm width) maintains geometric similarity to the original 5mm disc, though dimensional differences may require PCB footprint verification. Moisture sensitivity is listed as not applicable, differing from the original MSL-1 rating.

Frequently Asked Questions (FAQ)

Q: Can AL03006-165.9-55-G1 be used as a direct replacement without PCB modification?

A: No. The AL03006-165.9-55-G1 uses DO-204AH/DO-35 axial package geometry, while the original ERT-D2FFL251S uses a 5mm disc format. PCB footprint and component