LR2512H Metal Alloy Low-Resistance Resistors
The LR2512H is a lead-free, halogen-free, RoHS-compliant metal alloy low-resistance resistor in the 2512 SMD footprint, distinguished from the standard LR2512 by the addition of an integrated heat sink element on the underside of the component body. This heat sink tab conducts dissipated power directly into the PCB copper or an external thermal pad, extending the effective power rating to 3W and enabling higher continuous currents within the same 6.25mm × 3.20mm board area.
The resistance range spans 10.1mΩ to 80.0mΩ for the 3W rating and 12mΩ to 200mΩ for the 2W rating, with a TCR of ±50ppm/°C across the 10.1mΩ to 80.0mΩ range and ±50ppm/°C to ±100ppm/°C for the 2W variants depending on resistance value. Tolerance options are ±1%, ±2%, and ±5%. The rated continuous current for the 3W variant is 17.3A, with a short-time overload current of 38.54A. The operating temperature range is −55°C to +170°C. Components are supplied on 12mm tape and reel at up to 2000 pieces per reel for automated surface-mount placement.
What are the LR2512H Metal Alloy Low-Resistance Resistors?
The LR2512H is a surface-mount current sensing resistor that addresses the thermal limitation of the standard 2512 package at elevated power levels. In a conventional 2512 resistor, heat generated in the resistive element must escape primarily through the solder joints at the two end terminals, which constrains steady-state power dissipation. The LR2512H adds a metal heat sink tab to the body, providing a third thermal path that conducts heat away from the element through a larger contact area to the PCB, substantially reducing thermal resistance and allowing the component to sustain 3W without derating the resistance element itself.
The metal alloy resistive element delivers the stable, low-TCR characteristics needed for accurate current measurement over temperature. The ±50ppm/°C TCR across the 10.1mΩ to 80.0mΩ range means that resistance varies by no more than 0.005% per degree Celsius, keeping measurement error small across the full operating range without requiring external temperature compensation. This is particularly relevant in applications where the resistor operates at elevated temperatures due to the currents being measured.
The two-terminal solder-pad layout is compatible with standard 2512 land patterns, and the heat sink tab occupies the central underside region of the body with a tab thickness of 0.1mm to 1.0mm, which solders to a thermal pad on the PCB during reflow. This arrangement means the LR2512H can be placed and reflowed on the same production line as other SMD components without additional assembly steps, while gaining the thermal benefit of the heat sink for the high-dissipation variants in the range.
Environmental qualification follows JIS C5201-1 and MIL-STD-202 test methods, covering solder heat resistance at 260°C, solderability at 245°C, 1000-hour high-temperature storage at +170°C, 1000-hour low-temperature storage at −55°C, 1000-cycle rapid temperature change from −55°C to +150°C, moisture resistance, bias humidity at 85°C and 85% RH for 1000 hours, and a 1000-hour load life test. Short-time overload resistance change is specified at no more than ±0.5% under five times rated power for five seconds, confirming robustness to the transient overcurrents typical of motor start-up, inrush events, and short-circuit detection scenarios.
LR2512H Metal Alloy Low-Resistance Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
Model: LR2512H
Resistor type: Metal alloy
Description: Low resistance
Power Rating: 2W~3W
Rated Current: 17.3A
Resistance (Ω): 10m~80m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 50
Applications of the LR2512H Metal Alloy Low-Resistance Resistors
Where RARA metal clad resistors are deployed in the field.
Power supply output current sensing — monitoring load current in switched-mode power supplies where the 3W rating and low TCR support accurate, thermally stable measurement at medium to high output currents within a compact SMD footprint.
Battery management systems — charge and discharge current measurement in lithium-ion and other battery chemistries, where the higher power rating accommodates the elevated currents of fast-charge and high-capacity cell configurations.
Motor drive and inverter circuits — phase or DC bus current sensing in brushless DC motor drives and variable frequency drives, where transient overcurrents during start-up or braking demand the short-time overload robustness of the metal alloy element.
DC-DC converters — input and output current sensing in synchronous buck and boost converters for peak current mode control, overcurrent protection, and power path management in space-constrained designs.
On-board chargers and bidirectional converters in automotive and EV applications — current sensing in medium-power conversion stages where RoHS and halogen-free compliance, extended temperature range, and stable TCR are mandatory requirements.
Industrial automation and servo drives — current feedback in servo amplifiers and motion control systems, where the combination of accurate measurement and 3W continuous dissipation capacity supports high-dynamic-range current sensing.
Renewable energy inverters and energy storage systems — current measurement in grid-tie inverters, off-grid converters, and battery energy storage units operating across wide ambient temperature ranges.
Telecommunications and data centre power distribution — load current monitoring in intermediate bus converters and point-of-load regulators, where board space is constrained and per-channel power dissipation must be managed within the 2512 footprint.
Related Products of the LR2512H Metal Alloy Low-Resistance Resistors
Model: MFF
Resistor type: Metal foil
Description: Low resistance chip
Power Rating: 0.33W~4W
Resistance (Ω): 0.5m~100m
Tolerance (%): ±0.3, ±0.5, ±1
TCR (ppm/C): 30-100
Model: MFR (Metal foil)
Resistor type: Metal foil
Description: Low resistance chip
Power Rating: 0.33W~5W
Resistance (Ω): 1m~700m
Tolerance (%): ±0.5, ±1
TCR (ppm/C): 50, 75, 100
Model: LRE
Resistor type: Metal alloy
Description: Low resistance
Power Rating: 1/6W~1W
Resistance (Ω): 0.2m~300m
Tolerance (%): ±0.5, ±1, ±2, ±5
TCR (ppm/C): 1-175
Model: MR
Resistor type: Metal alloy
Description: Low resistance
Power Rating: 2W, 3W, 5W
Resistance (Ω): 4m~100m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 50, 75, 200
Why Choose RARA Current Sensing Resistors
What sets RARA apart for engineers and procurement managers in industrial and automotive markets.
01
8 Sub-Categories
No other single supplier covers AEC-Q200 chip shunts, milliohm precision types, four-terminal Kelvin shunts, power metering, and 12,000A panel shunts under one ISO-certified roof.
02
Extreme Precision
HPS, UHPS, and PSS precision shunts deliver ±0.05% tolerance and 3 ppm/°C TCR — meeting the accuracy demands of EV battery coulomb counting, precision power analyzers, and billing-grade energy metering.
03
Automotive Qualified
Multiple AEC-Q200 certified models (BCS, LRA, ECS, BWR, TCS, PCBS) with IATF 16949 manufacturing certification — covering EV battery management, motor control, and charging applications.
04
Global Track Record
Trusted by Tesla, GM Korea, Proterra, Siemens, Rockwell, and Schneider Electric — deployed in EV powertrains, industrial drives, and utility metering systems across six continents.
