MELF Fusible Wirewound Film Fixed Resistor applies to electric light sources, switching power supplies, chargers, communication equipment, medical electronic equipment, test and measurement equipment, automobiles. Replacing plug-in resistors in electronic equipment such as electronics, industrial products, and household appliances.
MELF Fusible Wirewound Film Fixed Resistor
Scope Of MELF Fusible Wirewound Film Fixed Resistor
This standard applies to electric light sources, switching power supplies, chargers, communication equipment, medical electronic equipment, test and measurement equipment, automobiles.
Replacing plug-in resistors in electronic equipment such as electronics, industrial products, and household appliances.
Features Of MELF Fusible Wirewound Film Fixed Resistor
1) Use non-combustible / epoxy resin coatings with safety features of non-combustible and insulating;
2) Miniaturization for high-density placement;
3) Meet the requirements of lead-free (Pb) and lead-containing soldering processes;
4) Can be used in automatic surface mount (SMD) assembly systems. Suitable for automatic welding by wave soldering and reflow soldering
Power Derating curve Of MELF Fusible Wirewound Film Fixed Resistor
Structure dimension Of MELF Fusible Wirewound Film Fixed Resistor
| Size | Dimension(mm) | ||
| L | D1 | D2 Max. | |
| 0204 | 3.5±0.2 | 1.1±0.1 | 1.4±0.2 |
| 0207 | 5.9±0.2 | 1.7±0.1 | 2.1±0.2 |
| 0309 |
Single cap 8.5±0.2 Double cap 8.7±0.2 |
2.5±0.1 |
Single cap 3.1±0.2 Double cap 3.0±0.2 |
Material list Of MELF Fusible Wirewound Film Fixed Resistor
| Code | Name | Material |
| 1 | Coating | Non-combustible / epoxy resin coating |
| 2 | Color ring | Flame retardant coating |
| 3 | Cuting wire | -- |
| 4 | Fuse element | Alloy wire |
| 5 | Magnetic bar | Alumina ceramic body / resistive film |
| 6 | Cap | Tinned iron cap |
Part Numbering Of MELF Fusible Wirewound Film Fixed Resistor
| KNPM | 1 | 100 | J | S | 0309 |
KNPM : Series name
1 : Power Rating -- 0.125W,0.25W,0.5W,1W,2W.
100 : Resistance value -- E24 norminal resistance
J : Resistance tolerance -- F=±1%,G=±2%,J=±5%
S : Size code -- It is normal size without code; S- small size ; X-Ultra-small size.
Electrical Performances Of MELF Fusible Wirewound Film Fixed Resistor
| Size Type | Power range(70C) | Temperature range℃ | Insulation voltage V | Resistance range(Ω) |
| ±1%,±2%,±5% | ||||
| 0204 |
0.125W 0.25WS 0.5W-X |
-55～155 | 200 |
MFM 0.1～2.2M CFM 1～10M MOFM 1～10K |
| 0207 |
0.25W 0.5W-S 1W-X |
-55～155 | 250 |
KNPM 0.22～100 MFM 0.1～10M CFM 1～10M MOFM 1～10K |
| 0309 |
0. 5W 1W-S 2W-X |
-55～155 | 350 |
KNPM 0.22～300 MFM 0.1～10M CFM 1～10M MOFM 1～10K |
General Data Of MELF Fusible Wirewound Film Fixed Resistor
| Nominal resistance tolerance | ± 5% |
| Climate category | 55/155/21 |
| Low air pressure | 8.5kpa |
| Stability level | 5% |
| Resistance change | Limit value |
| Long-term test | ±(5%R+0.1Ω) |
| Short-term test | ± (1% R + 0.05 Ω) |
| Rated current | I2(A)=P(W)/R(Ω) |
Package quantity & size Of MELF Fusible Wirewound Film Fixed Resistor
9.1 Tape Size
| Size |
φA (mm) |
φB (mm) |
φC (mm) |
W | T | QTY(pcs) |
| 0204 | 179±2 | 60±2 | 13±0.5 | 9±1 | 12±0.5 | 3000 |
| 0207 | 179/330±2 | 90±2 | 13±0.5 | 10±1 | 14.5±1 | 2000/5000 |
| 0309 | 330±2 | 90±2 | 13±0.5 | 16±1 | 19.5±1 | 2500 |
9.2 Paper size Of MELF Fusible Wirewound Film Fixed Resistor
| Size | Dimension(mm) | ||||
| A | B | W | E | F | |
| 0204 | 1.6±0.2 | 3.8±0.2 | 8.0±0.2 | 1.75±0.1 | 5.25±0.1 |
| 0207 | 2.4±0.2 | 6.0±0.2 | 12.0±0.2 | 1.75±0.1 | 7.25±0.1 |
| 0309 | 3.6±0.2 | 8.9±0.2 | 16.0±0.2 | 1.75±0.1 | 9.25±0.1 |
| P0 | P1 | P2 | D0 | T | |
| 0204 | 4.0±0.1 | 4.0±0.1 | 2.0±0.1 | 1.5±0.1 | 1.65±0.1 |
| 0207 | 4.0±0.1 | 4.0±0.1 | 2.0±0.1 | 1.5±0.1 | 2.5±0.1 |
| 0309 | 4.0±0.1 | 8.0±0.1 | 2.0±0.1 | 1.5±0.1 | 3.5±0.1 |
Color marking Of MELF Fusible Wirewound Film Fixed Resistor
| Color | First digit | Second digit | Third digit | Malutiplier | Tolerance |
| Black | 0 | 0 | 0 | 100 | - |
| Brown | 1 | 1 | 1 | 101 | ±1 |
| Red | 2 | 2 | 2 | 102 | ±2 |
| Orange | 3 | 3 | 3 | 103 | - |
| Yellow | 4 | 4 | 4 | 104 | - |
| Green | 5 | 5 | 5 | 105 | ±0.5 |
| Blue | 6 | 6 | 6 | 106 | ±0.25 |
| Violet | 7 | 7 | 7 | 107 | ±0.1 |
| Gray | 8 | 8 | 8 | 108 | - |
| White | 9 | 9 | 9 | 109 | - |
| Gold | - | - | - | 10-1 | ±5 |
| Sliver | - | - | - | 10-2 | ±10 |
| Plain | - | - | - | - | - |
Performance Specifications Of MELF Fusible Wirewound Film Fixed Resistor
| Characteristics | Test Conditions | Limits |
| Short Time Over Load | IEC 60115-1 4.13 5 seconds 2.5x rated voltage (not over max. overload voltage) | ±2% |
| Load Life In Humidity | IEC 60115-1 4.24 56 days rated load (not over max. working voltage) at (40±2)°C and (93±3)% relative humidity | |
| Load Life 1,000 hours | IEC 60115-1 4.25.1 Rated load (not over max. working voltage) with 1.5 hours ON, 0.5 hours OFF, at (70±2)°C | ±5% |
| Resistance To Soldering Heat | IEC 60115-1 4.18.2 Dip the resistor into a solder bath measured (260±5)°C and hold it for a 10±1 seconds | ±1% |
| Solderability | IEC 60115-1 4.17.2 Solder area covered after (230±3)°C/(2±0.2) seconds with flux applied | 95% Min. |
| Vibration | IEC 60115 4.22 Six hours in each parallel and axial direction with a simple harmonic motion having an amplitude of 0.75mm and 10 to 500 Hz. | ±1% |
| Thermal Endurance | IEC 60115-1 4.25.3 1000 hours at 200°C without load | ±1% |
| Thermal Shock | IEC 60115-1 4.19 -55°C 30minutes, +155°C 30minutes, 5 cycles | ±3% |
| Surge Test | Surge voltage = DC P is power rating, R is resistance value, surge voltage is not more than listed at right. Surge spec = 1.2/50µs Period = 60 sec Number of surges = 100 |
±5% |
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