Introduction to Model Parameters of 2512 1.02R Metal Film Resistance

This is an introduction about the 1.02 Ω resistor in the 2512 package, highlighting the two specific part numbers you provided: EGM25FU1R02DDS and EAM25FS1R02DDS.

Overview of Core Parameters (2512 1.02R)

Package size: 2512 (6.35mm x 3.18mm) is a larger size that facilitates heat dissipation and carries higher power/current.
Nominal resistance: 1.02 Ω (ohms) low resistance, commonly used in current detection, current limiting, voltage division, and other applications that require small resistance values.
Resistance type: Metal film resistors usually have good accuracy, temperature stability, and low noise characteristics.
Accuracy (tolerance): ± 1% meets the requirements for resistance accuracy in most conventional applications.
Temperature coefficient (TCR): ± 50 ppm/° C means that for every 1 degree Celsius change in temperature, the resistance value does not change by more than 0.005%. This is a relatively stable indicator suitable for environments with little variation in working temperature.

Comparison of Key Item Numbers and Highlighting Characteristics

Although both resistors are metal film resistors with 2512 package, 1.02 Ω, 1% accuracy, and 50ppm TCR, their core differentiation design goals and key performance parameters are significantly different:

1. EGM25FU1R02DDS High Power&Surge Resistance Expert
Core features:
High rated power: 3.5W, which is a very high power level among 2512 packaged resistors. This means that under normal working conditions, it can withstand a larger continuous current (calculated based on P=I ² R, the continuous current is about 1.86A).
Strong surge resistance: This is the core design goal of this model. It has specially optimized its structure and materials to withstand instantaneous pulse power (surge current) much higher than the rated power.
Working principle/design:
Usually, special ceramic substrates, thicker metal film layers, or spiral cutting designs are used to disperse the heat generated by instantaneous high currents, avoiding film melting or substrate cracking.
Possible use of materials with higher melting points or structures that are more resistant to thermal shock.
Typical application scenarios:
Power input/output filtering: capable of withstanding surge currents caused by power on/off, lightning strikes, or sudden load changes.
Motor drive: withstand the high current impact generated when the motor starts or stalls.
Surge protection circuit (such as NTC bypass): As a current limiting resistor, it needs to withstand the initial surge.
High current switching power supply: As a current detection resistor or buffering resistor, it may encounter switch spikes.
Any circuit that needs to withstand high pulse energy.
Key selection points: This model is preferred when your application has sustained high power consumption (close to or exceeding 2W) or significant, unpredictable instantaneous high current (surge) risks. Its 3.5W power provides greater design margin.

2. EAM25FS1R02DDS Anti Sulfurization Corrosion Defender
Core features:
Sulfurization resistance: This is the core design goal of this model. It adopts special materials and processes, greatly improving the long-term reliability of resistors in sulfur-containing environments, preventing resistance drift and even open circuit failure caused by sulfurization corrosion.
Rated power: 2W This is the standard power rating for 2512 packaged resistors (at an ambient temperature of 70 ° C). The continuous current is about 1.4A.
Working principle/design:
Use sulfur resistant electrode materials such as pure tin (Sn) or special alloy coatings to replace traditional silver (Ag) or silver containing materials. Silver will generate high resistance silver sulfide (Ag ₂ S) in the presence of sulfides, leading to an increase in resistance or even an open circuit.
Adopting an anti sulfide protective layer/coating: applying an additional protective layer on the resistor or terminal electrode to block the penetration of sulfides.
Optimize the internal structural sealing.
Typical application scenarios:
Industrial automation equipment: Sulfur containing gases (such as hydrogen sulfide H ₂ S) are often present in factory environments.
Automotive electronics: Especially near the engine compartment, exhaust system, or enclosed modules, rubber parts may release sulfides.
Outdoor/harsh environment electronic devices: such as communication base stations, security equipment (sulfur-containing air pollution).
Lighting (especially LED drivers): Some sealed fixtures or materials may release sulfides.
Any equipment deployed in environments that may be contaminated with sulfides.
Key selection points: When your application is deployed in environments that may contain sulfides (industrial exhaust, automotive exhaust, volatile compounds from certain rubber/plastic seals, air in hot spring areas, etc.), this model is the key to ensuring long-term reliability. Even if the power demand is not high (2W is sufficient), it is necessary to choose a sulfur resistant model to avoid potential failure.

Summary and Comparison Table

|Features | EGM25FU1R02DDS | EAM25FS1R02DDS|
|Package | 2512 | 2512|
|Resistance | 1.02 Ω | 1.02 Ω|
|Accuracy | ± 1% | ± 1%|
| TCR           | ±50 ppm/°C                 | ±50 ppm/°C                  |
|Core advantages | High power (3.5W)&surge resistance | Resistance to sulfide corrosion|
|Rated power | 3.5W | 2W|
|Design objective | To withstand high sustained power and transient surges | To resist corrosion failure caused by sulfur-containing environments|
|Key materials/processes | Heat/impact resistant structures | Sulfurization resistant end electrodes&protective coatings|
|Typical applications | Power filtering, motor drive, high current switching power supply | Industrial, automotive electronics, outdoor equipment, harsh environments|

Conclusion:

EGM25FU1R02DDS and EAM25FS1R02DDS are both high-quality 2512 package 1.02 Ω metal film resistors, but they solve completely different engineering challenges:

Choose EGM25FU1R02DDS if your application has high power requirements (close to or exceeding 2W) or there is a serious risk of surge current. Its 3.5W power and surge resistant design are core values.
Choose EAM25FS1R02DDS if your application is deployed in environments that may contain sulfides (industrial, automotive, outdoor, etc.). Its sulfur resistance is the key to ensuring long-term reliability and avoiding failure caused by corrosion.

When selecting, it is necessary to make a decision based on the actual environmental conditions of the application (temperature, possibility of sulfide presence) and electrical requirements (continuous power, expected surge current). These two part numbers represent specialized solutions for specific reliability challenges based on common parameters.