Metal-Film Precision Resistors (MF)

Precision metal-film resistors for low-cost uses.

Direct offers a low-cost alternative commercial metal film resistor for precision applications. The MF series offers tight tolerances and low TCRs over a wide resistance range and are suitable for applications where long-term stability is paramount.

The MF is available in a resistance range of 10Ω to 1MΩ with a standard resistance tolerance of ±1% and a temperature coefficient of resistance (TCR) of +15/-25ppm/°C, although other tolerances and TCRs are available.

The resistance element in these devices is a precisely controlled thin film of metal alloy deposited on a high quality alumina rod. Plated caps are force-fitted before the assembly is trimmed using advanced trimming techniques to ensure excellent performance and low electrical noise.

Leads are welded to the end caps prior to the resistor being coated with epoxy, and colour band marking applied. A variety of standard lead forms are available for use where auto-insertion is not available or practical. This gives the advantage of the value being shown, even if the resistor is machine preformed or auto-inserted.

The MF is RoHS compliant with 100% lead free, Contact us with your specific needs.

Download complete PDF Metal-Film Precision Resistors (MF).

Features :
  1. Low cost, low noise, operating temperature range -55°C ~ 155°C
  2. Precision tighted tolerance available in ±0.1%, ±0.25%, ±0.5%, ±1%
  3. Pure tin plating provides compatibility with lead (Pb)-free and lead containing soldering processes
Applications :
  1. Telecom
  2. Test and measurement
  3. All general purpose applications
Dimensions & Specifications (Unit: mm) (MF)
STYLE MIL STYLE POWER RATING(W) DIMENSION (mm) MAX WORKING VOLTAGE MAX OVERLOAD VOLTAGE
RN RNS L D H d±0.05 RN RNS RN RNS
MF-12 RN-50 1/8W 1/4W 3.2± 0.2 1.5 ± 0.2 26 ± 1.0 0.40~0.45 200 150 400 300
MF-25 RN-55 1/4W 1/2W 6.0 ± 0.3 2.3 ± 0.3 26 ± 1.0 0.40~0.50 250 200 500 400
MF-50 RN-60 1/2W 1W 9.0 ± 0.5 3.0 ± 0.5 26 ± 1.0 0.50~0.55 350 250 700 500
MF-100 RN-65 1W 2W 11 ± 1.0 4.0 ± 0.5 35 ± 3.0 0.75~0.80 500 300 1000 600
MF-200 RN-70 2W 3W 15 ± 1.0 5.0 ± 0.5 35 ± 3.0 0.75~0.80 500 350 1000 700
Resistance Range (MF)
STYLE MIL STYLE TOLERANCE TC+15-25PPM TC+50PPM TC+100PPM REMARK
MF-12 RN-50 ±1%
±0.5%
±0.25%
100Ω-100KΩ
100Ω-100KΩ
100Ω-100KΩ
10Ω-1MΩ 10Ω-1MΩ *Standard resistance
is 10Ω-1MΩ,
below or over
this resistance
on request.
MF-25 RN-55 ±1%
±0.5%
±0.25%
±0.1%
51.1Ω-511KΩ
51.1Ω-511KΩ
100Ω-300KΩ
100Ω-300KΩ
10Ω-1MΩ 10Ω-1MΩ
MF-50 RN-60 ±1%
±0.5%
±0.25%
±0.1%
51.1Ω-1KΩ
51.1Ω-1KΩ
100Ω-551KΩ
100Ω-330KΩ
10Ω-1MΩ 10Ω-1MΩ
MF-100 RN-65 ±1%
±0.5%
±0.25%
±0.1%
51.1Ω-1KΩ
51.1Ω-1KΩ
100Ω-551KΩ
100Ω-330KΩ
10Ω-1MΩ 10Ω-1MΩ
MF-200 RN-70 ±1%
±0.5%
±0.25%
±0.1%
51.1Ω-1KΩ
51.1Ω-1KΩ
100Ω-551KΩ
100Ω-330KΩ
10Ω-1MΩ 10Ω-1MΩ
Electrical Performance (MF)
REQUIREMENTS CHARACTERISTICS JIS C 5202 MIL-R-10509F
Operating Temp. Range -55°C ~ 155°C    
Temp Coefficient (°C ) ±25 ±50 ±100 5.2 4.6.12
Short Time Overload ±(0.5%%+0.05Ω) 5.5 A 4.6.6
Dielectric Withstanding V ±(0.5%+0.05Ω) 5.7 A 4.6.8
Effect of Soldering ±(0.5%+0.05Ω) 6.4 350°C 3 sec 4.6.10
Temperature Cycling ±(0.5%+0.05Ω) 7.4 4.6.4
Low Temp Operation ±(0.5%+0.05Ω)   4.6.5
Terminal Strength ±(0.5%+0.05Ω) 6.1 4.6.7
Moisture Resistance ±(1%+0.05Ω) 7.9   1,000hr MIL R-22684 4.6.10
Load Life ±(1%+0.05Ω) 7.10   1,000hr 4.6.13
Storage ±(0.2%+0.05Ω) Shelved one year in a room of normal temperature and humidity
Order Codes (MF)
MF-25 1/4W 100R J TB
Type
MF
Power Rating
(W)
Resistance Value
(Ω)
10R 10Ω
100R 100Ω
1K 1KΩ
1M 1MΩ
Resistance Tolerance
(%)
J ±5%
Package
P Bulk
TB Taping Box