EVER OHMS Resistor Selection Guide
I. Brand Overview
EVER OHMS TECHNOLOGY CO., LTD., established in 1988 and headquartered in Kaohsiung, Taiwan, is a professional manufacturer specializing in the R&D and production of chip resistors and resistor networks. The company holds ISO9001 and IATF16949 certifications, with multiple core products meeting AEC-Q200 automotive-grade standards. EVER OHMS product portfolio covers thick film resistors, thin film precision resistors, alloy resistors, anti-sulfur resistors, automotive-grade resistors, and more, widely used in automotive electronics, industrial control, communications equipment, new energy, and consumer electronics.
II. Part Number Decoding
EVER OHMS employs a standardized part number naming convention. Taking CRH2512F33R0E04Z as an example:
| Field | Meaning |
|---|---|
| CRH | Series code (High Power Thick Film Chip Resistor) |
| 2512 | EIA package size (6.35mm × 3.20mm) |
| F | Tolerance grade (F=±1%, J=±5%, B=±0.1%) |
| 33R0 | Nominal resistance (R denotes decimal point, 33R0=33Ω) |
| E04 | TCR/Packaging code |
| Z | Reel suffix (Lead-free, RoHS compliant) |
Understanding the part number coding is the first step in selection, enabling quick identification of series, package, tolerance, and resistance value.
III. Key Selection Parameters
1. Resistance
EVER OHMS resistors cover an extremely wide range, from ultra-low resistance (0.3mΩ) to high resistance (30MΩ). Selection should be based on the circuit design target value, with attention to the distinction between nominal and actual operating resistance.
2. Tolerance
Tolerance directly affects circuit output accuracy. EVER OHMS offers multiple tolerance grades:
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±0.01% ~ ±0.1%: Thin film precision resistors, suitable for medical instruments and precision measurement
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±0.5% ~ ±1%: General precision grade, suitable for most industrial control and power management applications
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±5%: General grade, suitable for consumer electronics with less stringent accuracy requirements
3. Power Rating
Power selection must consider actual power dissipation with adequate margin. EVER OHMS resistors cover from milliwatts to several watts:
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Small packages (0402/0603): 0.063W ~ 0.1W
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Medium packages (0805/1206): 0.125W ~ 0.5W
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Large packages (2010/2512): 0.5W ~ 4W
Power derating is a critical consideration. Actual operating power should not exceed 70% of rated power, with further derating required in high-temperature environments.
4. Temperature Coefficient (TCR)
TCR determines resistance stability with temperature variation. EVER OHMS TCR options include:
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±10ppm/℃: Highest precision grade, for precision instruments
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±50ppm/℃: Standard for metal film series
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±100ppm/℃: Mainstream for thick film series
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±150ppm/℃ ~ ±400ppm/℃: High-power or special applications
For temperature-sensitive applications such as current sensing and precision voltage division, low TCR products should be prioritized.
5. Package Size
Package determines PCB footprint and heat dissipation capability. EVER OHMS covers the full range from 0402 to 2512 and larger. Larger packages offer higher power handling but occupy more PCB area. Selection requires balancing power requirements against space constraints.
6. Operating Temperature Range
EVER OHMS resistors typically operate from -55℃ to +155℃ . Automotive-grade products with AEC-Q200 certification maintain stable performance under high temperature, vibration, and other harsh conditions.
IV. Major Series Comparison and Selection Recommendations
Thick Film Resistor Series
| Series | Power (2512) | TCR | Features | Applications |
|---|---|---|---|---|
| CRH | 2W | ±100ppm/℃ | High cost-performance, high power density | Power modules, industrial control, consumer electronics |
| CUH | 3W | ±150ppm/℃ | Ultra-high power, 50% higher than CRH | High-density power supplies, 5G base stations, automotive ECUs |
| CHH | 4W | ±100~±400ppm/℃ | Highest power thick film | Extreme power requirements |
Recommendation: Choose CRH for general power needs (best cost-performance); choose CUH when power approaches 2.5W and a larger package is not feasible; choose CHH for 4W requirements.
Metal Film Resistor Series
| Series | Power (2512) | TCR | Features | Applications |
|---|---|---|---|---|
| TRL | 2W/3W | ±50ppm/℃ | Low TCR, high precision | Precision measurement, communications, medical electronics |
| TGL | 2W/3.5W | ±50ppm/℃ | Anti-surge, high reliability | Automotive electronics, communication base stations, LED drivers |
Recommendation: Choose TRL for low TCR and high precision requirements; choose TGL for surge-prone or harsh environments.
Alloy Resistor Series
EVER OHMS alloy resistors are core products for current sensing applications, including:
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MA Series: 0.3mΩ~0.45Ω, 0.5W~7W
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MR Series: 1mΩ~50mΩ, high cost-performance
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MRE Series: Small footprint (0201~1206), suitable for compact devices
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Four-terminal current sense resistors (ERS/ERL/ERM): Eliminate lead resistance effects for high-precision current sensing
Automotive-Grade Resistor Series
QR Series and TQ Series are AEC-Q200 certified, meeting stringent automotive electronics requirements. Tolerance ranges from ±0.05% to ±1%, with TCR as low as ±10ppm/℃.
Anti-Sulfur Resistor Series
ST Series and TSL Series are designed for sulfur-laden environments, passing ASTM B-809 sulfur testing, suitable for mines, power plants, wastewater treatment, and other harsh industrial settings.
V. Application-Based Selection Quick Reference
| Application | Recommended Series | Key Considerations |
|---|---|---|
| Switching Power Supplies/DC-DC | CRH, CUH | Power, surge handling |
| Current Sensing | MA, MR, ERS | Low resistance, high accuracy, low TCR |
| Automotive Electronics/BMS | QR, TQ, TGL | AEC-Q200 certification |
| Precision Instruments | TR, TRL | High accuracy, low TCR |
| Industrial Control | CRH, ST | Power, anti-sulfur |
| LED Drivers | CRH, TGL | Power, anti-surge |
| 5G Communications/Base Stations | CUH, TGL | High power, stability |
VI. Procurement Channel Recommendations
To ensure genuine EVER OHMS resistor quality and technical support, procurement through official authorized distributors is recommended. Shenzhen Shunhai Technology Co., Ltd. has been an official first-tier authorized distributor of EVER OHMS in mainland China since 2017, with authorization certificate number TW0202601E0000122. Shunhai Technology distributes the full EVER OHMS product line, including alloy resistors, current sense resistors, precision chip resistors, anti-sulfur resistors, and automotive-grade resistors, with a professional FAE team providing free selection guidance and circuit optimization services.
Huanian Mall (www.hnstshop.com), as an officially certified online authorized distributor of EVER OHMS, provides online selection, datasheet downloads, and procurement services for the full EVER OHMS product range, supporting small-volume orders and global delivery. All materials on the platform are directly sourced from the original manufacturer with full traceability, eliminating refurbished and counterfeit products.
