LRF12 Current Detection Resistor
Products Specifications
- Package
- 1206 (3116 Metric)
- Features
- Current Sense, Industrial Grade, Large Electrode, Good Performance for Heat Dissipation, High Purity Alumina Substrate for High Power Dissipation
- Series
- LRF12
- Operating Temperature
- -55℃ ~ +155℃
- Temperature Coefficient
- ±100ppm/°C
- Resistance
- 470 mOhms
- Power Rating
- 1W
- Tolerance
- 2.0%
- Mounting
- SMD / SMT
- Style
- Surface Mount Current Sensing Reistors
- Termination
- 2-Terminal
- Composition
- Metal Foil

Description
- Low Resistance and High Accuracy Resistor for Current Detection
- Large Electrode (All series)
- Good Performance for Heat Dissipation
- High Purity Alumina Substrate for High Power Dissipation
- Pb-free to Meet RoHS Requirements
Part Numbering System

| Parameter | Standard |
|---|---|
| Power Rating | 1206: 1W |
| Resistance Value | 100~910mΩ |
| Operating Temperature Range | -55 to +155°C |
| Component Temperature Coefficient (TCR) | ± 100 ppm/°C |
| Maximum Working Voltage (V) | (P/R)1/2 |
| Rating Current (A) | (P/R)1/2 |
P=Power Rating; R=Resistance Value
Standard Electrical Specifications
| Type | Rating Power at 70℃ | T.C.R. (ppm/℃) | Resistance Range(mΩ) 1.0%( F) 2.0%( G) 5.0%( J) | Operating Temperature(℃) |
|---|---|---|---|---|
| LRF12 | 1W | 100 | 100-910 | -55~+155°C |
Dimensions

Unit: mm
| Type | L | W | C | d | t |
|---|---|---|---|---|---|
| LRF 12 | 3.1 ±0.2 | 1.55 ±0.2 | 0.5±0.3 | 0.4±0.2 | 0.55± 0.1 |
Recommended land pattern

Unit: mm
| Type | a | b | c |
| LRF12 | 1.6~2.0 | 4.4~5.0 | 1.2~1.8 |
Derating Curve
For resistors operated at ambient temperature over 70℃, power rating shall be derated in accordance with figure 1.

IR Reflow-Soldering Profile

| Reflow Condition | Pb - Free assembly | |
| Pre heat | - Temperature Min (Ts ( min)) | 150℃ |
| - Temperature Max (Ts ( max)) | 200℃ | |
| - Time ( Min to Max ) (ts) | 60 - 120 secs | |
| Average ramp up rate (Ts max to Tp) | 3℃/second max | |
| Ts(max) to TL - Ramp-up Rate | 5℃/second max | |
| Reflow | - Temperature (TL) (Liquidus) | 217℃ |
| - Time (tL) | 60 - 150 seconds | |
| Peak Temperature (Tp) | 260℃ | |
| Time within +0/-5 ℃ of actual Peak Temperature (tp)² | 10 seconds | |
| Ramp-down Rate | 6℃/second max | |
| Time 25℃ to peak Temperature (Tp) | 8 minutes Max. | |
Product Characteristics
| Item | Test condition | Limited | Methods |
| Short Time Over load | 5 X rated power for 5 sec | ±(1% +0.5mΩ) | IEC60115-14.3 JIS-C5201-1-4.13 |
| Temperature Coefficient of Resistance | TCR (ppm/℃)=(R2-R1/R1*(T2-T1))X106 | Refer to 2 | Refer to JIS C 5201-1 4.8 |
| Biased Humidity | 10% Rated power at 85℃, RH:85%, 1000Hrs, Measurement at 24hrs after test conclusion |
± (5.0% + 0.5mΩ) | Refer to MIL-STD-202 Method 103 |
| Endurance (Load Life) | 1000 hours at rated power, 70℃, 1.5hours "ON", 0.5hour "OFF" | ± (5.0% + 0.5mΩ) | IEC60115-1-4.25.1 JIS-C5201-1-4.25.1 |
| Rapid Change of Temperature | -55℃ (15 min.)/+150(15 min.) 1000 cycles | ± (1.0% + 0.5mΩ) | IEC60115-1-4.19 JIS-C5201-1-4.19 |
| Solderability | 245±5℃ solder, 2±0.5 sec dwell. Solder: Sn96.5 / Ag3.0 / Cu0.5 | At least 95% of surface area of electrode shall be covered with new solder. | IEC60115-1-4.17 JIS-C5201-1-4.17 |
| Resistance to Solder Heat | 270 ±5℃ solder, 10±1 sec dwell. | ± (1.0% + 0.5mΩ) | IEC60115-1-4.18 JIS-C5201-1-4.18 |
| Robustness of Termination (Bending) | 2mm deflection | ± (1.0% + 0.5mΩ) | IEC60115-1-4.33 JIS-C5201-1-4.33 |
| High Temperature Exposure (Storage) | T=155℃, 1000HRS, Measurement at 24hrs after test conclusion. | ± (1.0% + 0.5mΩ) | Refer to MIL-STD-202 Method 108 |
Tapping & Package

Unit: mm
| Type | Pack | A ±0.2 |
B ±0.2 |
D0 +0.05/-0 |
E ±0.1 |
F ±0.05 |
P0 ±0.1 |
P1 ±0.1 |
P2 ±0.1 |
W ±0.2 |
T ±0.15 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1206 | Paper | 2.00 | 3.60 | 1.50 | 1.75 | 3.50 | 4.00 | 4.00 | 2.00 | 8.00 | 0.84 |
Reel Specification

Unit: mm
| Type | A | B | C | D | M | Wa | T |
|---|---|---|---|---|---|---|---|
| 1206 | 2.0±0.5 | 13.0±1.0 | 21.0±0.5 | 60.0±1.0 | 178.00±2.0 | 9.0±1.0 | 11.5±1.5 |
Packaging
Quantity: 1206: 5,000pcs
8mm wide tape on 178mm(7 inch) diameter reel -specification EIA Standard 481.
Peel strength of upper belt
Stripping speed: 300 mm / min; The peel force is between 0.1N and 0.7n.

Storage conditions & shelf life
It can be stored for 2 years under closed conditions with temperature of 5 ° C ~ 35 ° C and relative humidity of 40 ~ 75.
Please avoid the following harsh environment during storage to avoid affecting the product performance and solder connectivity: the places with corrosive gases such as sea breeze, Cl₂, H₂S, NH₃, SO₂ and NO₂ shall be stored without direct sunlight.
Precautions for product use
When measuring the resistance value before welding, a special resistance meter with high precision shall be used. When measuring, a 4-wire probe or fixture must be used. 4. When measuring parts with a wire measuring needle, the 4 measuring needles must indeed contact the parts.
Avoid damaging the protective layer during manual welding or clamping with tweezers.
When the PCB is divided or fixed on the support, be careful to avoid excessive bending causing mechanical stress to the resistor.
It shall be used within the rated power range within the specification, especially when the power exceeds the rated value, which may affect the reliability of the product.