Introduction to the naming convention of SUSUMU metal foil resistors

The naming of SUSUMU metal foil resistors follows strict logical rules, and by combining letters and numbers in the model, its technical parameters and application scenarios can be quickly analyzed. The following is a detailed breakdown of its naming system:
1、 Overview of Naming Structures
Typical model format: KRL+package size+resistance value code+precision/temperature coefficient+packaging form
Taking KRL6432E-M-R010-F-T5 as an example:
KRL: Series Identification (Metal Foil Material)
6432: Package size (length 6.4mm x width 3.2mm)
E: Resistance value code extension identifier
M: Accuracy level (± 1%)
R010: Resistance (0.01 Ω)
F: Packaging form (roll and tape packaging)
T5: Temperature coefficient grade (± 50ppm/℃)
2、 Segmented parsing rules
1. Series identification (first 3 letters)
KRL: Metal foil resistor series, full name Kyocera Resistor Low Temperature Coefficient.
Emphasize the use of metal foil technology to achieve low temperature coefficient and high precision.
2. Package size (4-digit number)
Format: The first two digits are length (inches x 100), and the last two digits are width (inches x 100).
Example:
6432 → 6.4mm (length) × 3.2mm (width), corresponding to EIA standard 2512 package.
1220 → 1.2mm × 2.0mm, corresponding to 0805 package.
Common packaging:
Miniaturization: 0402 (1005), 0603 (1608), 0805 (2012)
Power type: 1206 (3216), 2512 (6432), 3015 (7638)
3. Resistance value code (1 letter+3 digits)
Alphabet section:
E: Extended resistance identification, indicating that the resistance value includes a decimal point (e.g. R010=0.01 Ω).
No letters: directly represents the integer resistance value (such as R100=0.1 Ω, please note that the actual value is R100=0.1 Ω, but it needs to be confirmed based on the specific model).
Number section:
The first three digits: resistance code, using Scientific notation.
Example:
R010 → 0.01 Ω (R represents the decimal point, 010 is 10 ^ -3, i.e. 0.01=10 × 10 ⁻ ³)
R470 → 0.47Ω
1000 → 100 Ω (representing integers directly when there is no decimal point)
Special Value:
000: represents zero ohm jumper resistance (for specific packaging only).
4. Accuracy and temperature coefficient (1 letter+1 digit)
Accuracy level:
M: ± 1% (high precision)
K: ± 10% (universal accuracy)
Others: J (± 5%), F (± 1%), etc., need to be confirmed based on specific series.
Temperature coefficient (TCR):
T5: ± 50ppm/℃ (typical value, indicating a resistance change of 0.005% for every 1 ℃ temperature change)
T1: ± 25ppm/℃ (automotive grade low-temperature float)
T0: ± 10ppm/℃ (ultra-low temperature float, medical grade specific)
5. Packaging form (1 letter)
F: Tape&Reel packaging, suitable for automated surface mount production.
B: Bulk, suitable for small batches or R&D testing.
K: Pre formed packaging (such as KRL-KIT kit), containing multiple resistance combinations.
3、 Naming Logic Example Analysis
Taking KRL1220E-M-R010-F-T5 as an example:
KRL → Metal foil resistor series
1220 → 0805 package (1.2mm × 2.0mm)
E → Resistance value including decimal point
M → Accuracy ± 1%
R010 → Resistance value 0.01 Ω
F → Tape packaging
T5 → Temperature coefficient ± 50ppm/℃
Application scenario: Current detection in the Battery Management System (BMS) of new energy vehicles requires high precision and low temperature drift characteristics.
4、 Special model extension rules
Anti sulfurization model: Add - S suffix to the model (such as KRL6432E-M-R010-F-T5-S), and use a special coating to prevent sulfurization corrosion.
Vehicle grade certification: Models that have passed AEC-Q200 are marked in the data manual, and the model itself is not reflected. It needs to be confirmed through parameter screening.
High power models: Package size suffix - HP (such as KRL3015-HP), supporting higher rated power (such as 4W).
5、 Selection Tool and Data Manual
The SUSUMU official website provides parameter filters and model comparison tables, and users can quickly locate the model through the following steps:
Input parameters such as resistance range, packaging size, accuracy, etc.
The system generates a matching model list and associates it with a data manual (including detailed electrical characteristic curves).
The data manual provides a naming convention lookup table to assist in verifying model analysis.
By mastering the above naming logic, users can quickly extract key parameters from the model, achieving efficient selection and inventory management.