Version:
July 20, 2018
Melf Resistor Series
Token Electronics Industry Co., Ltd.
Web: www.token.com.tw
Email: rfq@token.com.tw
Taiwan: No.137, Sec. 1, Zhongxing Rd., Wugu District,
New Taipei City, Taiwan, R.O.C. 24872
Tel: +886 2981 0109
Fax: +886 2988 7487
China:
12F, Zhong Xing Industry Bld., Chuang Ye Road,
Nan Shan District, Shen Zhen City,
Guang Dong, China 518054
Tel: +86 755 26055363; Fax: +86 755 26055365
Production Index
Melf Resistor Series
Terminology & Glossary ...................................................................................... 1
Terminology & Glossary..................................................................................... 1
Low Noise Carbon MELF Resistors (RDM) ........................................................ 3
Product Introduction ........................................................................................... 3
Dimensions ........................................................................................................ 4
Characteristics .................................................................................................... 5
Order Codes ....................................................................................................... 5
Non-Inductive Melf Resistors (RFM)................................................................... 6
Product Introduction ........................................................................................... 6
Dimensions ........................................................................................................ 7
Characteristics .................................................................................................... 8
Order Codes ....................................................................................................... 8
Pulse Load Melf Resistors (RGM) ....................................................................... 9
Product Introduction ........................................................................................... 9
Dimensions .......................................................................................................10
Characteristics ................................................................................................... 11
Order Codes ...................................................................................................... 11
Metal Film Ultra Precision Melf Resistors (RJM) .............................................. 12
Product Introduction ..........................................................................................12
Dimensions .......................................................................................................13
Characteristics ...................................................................................................14
Order Codes ......................................................................................................14
General Information ..........................................................................................15
http://www.token.com.tw
rfq@token.com.tw
Taiwan Factory: +886 2 29810109
China Factory: +86 755 26055363
Index: I
Terminology & Glossary
Terminology & Glossary
Terminology & Glossary
Derating Curve
The curve that expresses the relation between the ambient temperature and the maximum value of
continuously loadable power at its temperature, which is generally expressed as a percentage.
Dielectric Withstanding Voltage
The rated voltage that can be applied to a designated point between the resistive element and the outer
coating, or the resistive element and the mounting surface, without causing dielectric breakdown.
Maximum Overload Voltage
The maximum value of voltage capable of being applied to resistors for a short period of time in the
overload test. Typically the applied voltage in the short time overload test is 2.5 times larger than the
rated voltage. However, it should not exceed the maximum overload voltage.
Maximum Working Voltage
The maximum value of DC voltage or AC voltage (rms) capable of being applied continuously to
resistors or element. However, the maximum value of the applicable voltage is the rated voltage at the
critical resistance value or lower.
Power Rating
Power ratings are based on physical size, allowable change in resistance over life, thermal conductivity
of materials, insulating and resistive materials, and ambient operating conditions. For best results,
employ the largest physical size resistors at less than their maximum rated temperature and power.
Rated Ambient Temperature
The maximum ambient temperature at which resistors are capable of being used continuously with the
prescribed rated power. The rated ambient temperature refers to the temperature around the resistors
inside the equipment, not to the air temperature outside the equipment.
Rated Power
The maximum amount of power that can be continuously loaded to a resistor at a rated ambient
temperature. Network and array products have both rated power per package as well as per element.
Rated Voltage
The maximum value of DC voltage or AC voltage (rms) capable of being applied continuously to
resistors at the rated ambient temperature.
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rfq@token.com.tw
Taiwan Factory: +886 2 29810109
China Factory: +86 755 26055363
Page: 1/15
Resistor Tolerance
Resistor tolerance is expressed as the deviation from nominal value in percent and is measured at
25
℃
only with no appreciable power applied. A resistor's value will also change with applied voltage
(VCR) and temperature (TCR). For networks, absolute resistor tolerance refers to the overall tolerance
of the network. Ratio tolerance refers to the relationship of each resistor to the others in the package.
Temperature Coefficient of Resistance (TCR)
TCR is expressed as the change in resistance in ppm (0.0001 %) with each degree Celsius of change in
temperature. TCR is typically referenced at +25
℃
and changes as the temperature increases (or
decreases). A resistor with a TCR of 100 ppm/℃ will change 0.1 % over a 10
℃
change and 1 %
over a 100
℃
change. In the context of a resistor network, the TCR value is called the absolute TCR
in that it defines the TCR of a specific resistor element. The term TCR tracking refers to the difference
in TCR between each specific resistor in a network.
MELF Resistor - Alias & Acronym
Melf is the abbreviation of "Metal Electrode Leadless Face" and is a cylindrically shaped resistor
designed for surface mounting.
Acronym: Leadless Resistor; Cylindrical Resistor; Metal Electrode Leadless Face device; Surface
Mounted Leadless Component.
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rfq@token.com.tw
Taiwan Factory: +886 2 29810109
China Factory: +86 755 26055363
Page: 2/15
Low Noise Carbon MELF Resistors
(RDM)
Product Introduction
Token Carbon Film MELF (RDM) is the cost-effective option.
Features :
Applications :
Coating color: Yellow; Marking: Color code (3
Home appliances,
color band).
Electrical Equipment,
Free direction for mounting due to cylindrical
Consumer electronics.
design. Electrodes strength is higher than flat
chip resistors.
Specially plated electrodes for high solderability.
Lower current noise than flat chip resistors. Lead
(Pb)-free and RoHS compliant.
Speciality carbon film technology. DIN: 0204,
0207, 0309.
Commercial grade low power carbon film resistors offer high quality
performance for applications that do not require surge protection or
precision tolerances.
Providing design engineers with an economical power resistor with
high quality performance, Token Electronics now offers commercial
grade low power carbon film resistors. Designated the RDM Series,
the conformal coated resistors offer high quality performance for
applications that do not require surge protection or precision
tolerances.
The commercial grade carbon Melf resistors are available in flame retardant packaging and have ideal
specifications for consumer electronic or electrical devices. The RDM Series resistors offer a wide
resistance range for devices with power ratings below 1W, delivering high quality performance for
general purpose applications.
The RDM Series resistors are ideal for general use applications including electrical equipment, small
appliances and consumer electronics, such as televisions and other high-volume products.
The RDM Series film resistors feature power ratings from 0.125 to 1W, with a resistance range from 1
Ω to 1M Ω. Standard tolerances for the devices are to ±2% and ±5% with TCRs as low as ±300ppm/℃
for values of 1K Ω or less. Maximum working voltage ranges from 200V to 350V.
Contact our sales representative with your specific needs. Or you can link to Token official website
"Melf
Resistors"
for more information.
http://www.token.com.tw
rfq@token.com.tw
Taiwan Factory: +886 2 29810109
China Factory: +86 755 26055363
Page: 3/15
