Prosemicsr LMJ12 Current Sense Resistor
Product description
The LMJ12 series combines ultra-low resistance, minimal inductance, low thermal EMF, and robust all-metal construction to deliver precise current measurement with minimal parasitic effects. Advanced proprietary processing enables resistance values down to the sub-milliohm range, reducing insertion loss, while optimized geometry ensures fast transient response. Metal-to-metal interfaces are designed to suppress thermal voltages for improved accuracy, and the fully metallic body offers excellent mechanical strength, thermal conductivity, and long-term stability—making LMJ12 ideal for high-performance, high-reliability applications.
Product use
Current sense resistors, also known as shunt resistors, are used to measure current by converting it into a voltage, which can then be easily measured and monitored by a control circuit They are essential components in various applications where precise current monitoring and control are needed.
Current Monitoring & Protection
Current sense resistors convert circuit current into a small, measurable voltage drop—enabling precise overcurrent protection, short‑circuit detection, and load monitoring. For example, the LMJ12 series offers ultra‑low resistance values (1 mΩ to 200 mΩ) with power ratings up to 1 W, making them ideal for tight‑space power supplies, battery management systems (BMS), and LED drivers.
Dynamic Control & Efficiency Optimization
Accurate, real‑time current feedback is essential for torque control, stall protection, and voltage conversion efficiency in motor drives, DC–DC converters, and smart‑grid applications. The LMJ12’s tight temperature coefficient (as low as ±50 ppm/°C) ensures stability across varying loads and ambient temperatures, helping systems run cooler and more efficiently.
Safety & System Reliability
By feeding current data into diagnostic and thermal‑management circuits, sense resistors help prevent overheating, enable preventive maintenance, and maintain overall system integrity. Widely adopted in automotive ECUs, telecom racks, and medical instruments, the LMJ12 series—qualified to automotive AEC‑Q200 standards—provides the reliability these mission‑critical applications demand.
LMJ12 Series Specification、
| Type | Rating Power at 70℃ | T.C.R. (ppm/℃) | Resistance Range(mΩ) 0.5%（D） 1.0%（ F） 2.0%（ G） 5.0%（ J） | Meterial | Electrode | Operating Temperature(℃) |
|---|---|---|---|---|---|---|
| LMJ12 | 1W | 380 | 1~100 | R001~R100: MnCu | R001 | -55~+170°C |
| 50 | R001: (S) | |||||
| R002~R100 | ||||||
| 0.5W | 50 | 101~200 | R101~R200:MnCu | R101~R200 |
Notes:
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T.C.R. = Temperature Coefficient of Resistance
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Electrode codes “R001” through “R200” correspond to internal terminations tailored for low-ohmic stability.
Product Characteristics
| Item | Test condition/ Methods | Limited | Standard |
|---|---|---|---|
| Resistance | Measuring resistance value at room temperature 25℃±5℃ | Refer to Spec | IEC60115-1 4.5 |
| Temperature coefficient of resistance | TCR =(R-R0)/R0(T2-T1)X 106 R0 : resistance of room temperature R: resistance of 125℃ T1: Room temperature T2: Temperature at 125℃ |
Refer to Spec | MIL-STD-202 Method 304 |
| Short time Overload | 5×Rated power for 5 seconds | ≤±0.5% | MIL-STD-202 Method 210 |
| Resistance to Soldering Heat | 260℃± 5℃ time ：10sec± 1sec | ≤±0.5% | MIL-STD-202 Method 210 |
| Temperature Cycling | -55℃ (30min)/+125℃(30min), 1000 cycles | ≤±0.5% | MIL-STD-202 Method107G |
| Low temperature Storage | -55℃ for 1000hours, No power | ≤±0.5% | MIL-STD-26E |
| High Temperature Storage | 125℃ for 1000hours, No power | ≤±1% | IEC6011501-4.25 |
| Bias Humidity | +85℃, 85% RH ，10%bias, 1.5 h "ON", 0.5 h "OFF" ，1000hours | ≤±0.5% | MIL-STD-202 Method103 |
| Joint Strength of Solder | Soldered on the bending test plate, put on the bending testing machine, pressed under force in the center of the test plate, measure its resistance variance rate under load | ≤±0.5% | JIS-C5201 |
| Solderability | Temperature of Solder ：245±5℃ Dipping time:3±1s |
Solder coverage over 95% | IEC60115-1 4.17 |
| Load life | 1000 h at 70 °C , 1.5 h "ON", 0.5 h "OFF" | ≤±1% | JIS-C5201 |
| Operational life | 125℃± 3℃, 1000 hours, at rated power | ≤±0.5% | MIL-STD-202 Method 108 |