BWB Series AEC-Q200 Four-Terminal Chip Shunt Resistors
Four-terminal (Kelvin) configuration chip shunt resistor for precision high-current sensing in automotive and power electronics applications
Resistance range 0.2 mΩ to 5 mΩ
Power rating 2 W to 12 W depending on resistance value, referenced to terminal temperatures of 70°C and 100°C
Continuous current up to 100 A at 0.5 mΩ
TCR ≤50 ppm/°C maximum across the full resistance range
Tolerance options ±1%, ±2%, and ±5%
Two alloy materials: Copper Manganese Alloy for 0.2 mΩ to 1 mΩ; Aluchrom or NiCr Alloy for 2 mΩ to 5 mΩ
Applicable temperature range −55°C to +170°C
Maximum solder temperature 350°C for 30 seconds
AEC-Q200 qualified; RoHS and REACH certified
What are the BWB Series AEC-Q200 Four-Terminal Chip Shunt Resistors?
The BWB is a precision four-terminal chip shunt resistor designed for accurate current sensing in high-current automotive and power electronics applications. The defining characteristic of the BWB relative to conventional two-terminal shunts is its Kelvin, or four-terminal, connection arrangement. In a four-terminal configuration, the current-carrying terminals and the voltage-sensing terminals are physically separated: the full load current enters and exits through the outer current terminals, while the inner voltage terminals sample only the resistive voltage drop across the element itself, entirely free from the resistance and inductance of the solder joints and PCB traces at the current connections. This separation eliminates the contact resistance error that limits accuracy in two-terminal shunt measurements at very low resistance values and high currents, making the BWB suitable for applications where milliohm-level measurement uncertainty cannot be tolerated.
Nine resistance values span 0.2 mΩ to 5 mΩ within the single BWB package. Resistive alloy material is assigned by resistance value: Copper Manganese Alloy is used for the lower resistance values from 0.2 mΩ to 1 mΩ, where its high conductivity and controlled TCR deliver the required combination of low resistance and thermal stability. Aluchrom Alloy or NiCr Alloy is used for the higher resistance values from 2 mΩ to 5 mΩ, where the alloy composition is better matched to the element geometry at these resistance levels. A TCR of ≤50 ppm/°C is maintained across all values regardless of alloy selection. Power ratings are referenced to two terminal temperature conditions — 70°C and 100°C — to reflect the variation in allowable dissipation with the thermal environment of the mounting, with the 0.2 mΩ value rated at 12 W at 70°C terminal temperature and 5 W at 100°C terminal temperature. Continuous current capability reaches 100 A at the 0.5 mΩ resistance value.
The maximum solder temperature of 350°C for 30 seconds is notably higher than the 260°C limit typical of standard SMT components, providing process flexibility for assembly environments using higher-temperature solder alloys or demanding reflow profiles. The full AEC-Q200 reliability qualification covers high-temperature exposure at 170°C for 1000 hours unpowered to ±1.0%, temperature cycling from −55°C to 150°C over 1000 cycles with 30-minute dwell at each extreme to ±0.5%, biased humidity at 85°C and 85% RH with 10% operating power for 1000 hours to ±0.5%, operational life at 125°C at rated power for 1000 hours to ±1.0%, mechanical shock at 100 g half-sine for six milliseconds to ±0.2%, vibration at 5 g from 10 Hz to 2000 Hz across three orientations for 12 cycles to ±0.2%, short-time overload at five times rated power for five seconds to ±1.0%, and low-temperature storage at −65°C for 24 hours to ±0.2%.
BWB Series AEC-Q200 Four-Terminal Chip Shunt Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
Model: BWB
Resistor type: AEC-Q200
Description: Shunt
Power Rating: 2W~12W
Resistance (Ω): 0.2~5m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 50
Applications of the BWB Series AEC-Q200 Four-Terminal Chip Shunt Resistors
Where RARA metal clad resistors are deployed in the field.
Automotive battery management systems — four-terminal current sensing for state-of-charge and state-of-health monitoring in high-voltage EV and HEV battery packs, where the Kelvin connection eliminates solder joint resistance from the measurement path and supports the high accuracy required for reliable battery state estimation over the life of the vehicle
On-board charger current measurement — precision inline sensing of charge current in automotive AC-DC converters, where the four-terminal arrangement decouples the sense signal from the impedance of the high-current connections and the AEC-Q200 qualification confirms suitability for the thermal and vibration environment of the vehicle charging system
Power module current sensing — shunt measurement integrated within IGBT and SiC power modules or their gate driver PCBs, where the compact chip format and high solder temperature rating allow the BWB to be assembled alongside power semiconductors using the same reflow process without temperature-related reliability compromise
Frequency converter and variable-frequency drive current feedback — DC bus or phase current sensing in industrial and automotive frequency converters, where the Kelvin terminal configuration provides the accuracy needed for closed-loop current control and the ≤50 ppm/°C TCR maintains calibration stability across the converter operating temperature range
Automotive power distribution and smart fuse systems — current monitoring in intelligent fuse boxes and power distribution modules, where four-terminal sensing supports accurate overcurrent detection and load current reporting across the full range of automotive electrical loads from low-power accessories to high-current motor loads
DC-DC converter and voltage regulator current sensing — output current measurement in synchronous buck and boost converters for automotive auxiliary power supplies and 48 V mild-hybrid systems, where precise current feedback supports accurate regulation, load balancing, and protection in multi-phase converter designs
Industrial servo drive and motion control current measurement — phase or bus current sensing in high-performance servo amplifiers, where the four-terminal configuration eliminates the connection resistance error that would otherwise limit current loop bandwidth and torque linearity in precision motion control applications
Test and measurement reference shunts — precision calibrated shunts in power analysers, battery testers, and high-current measurement instrumentation, where the four-terminal connection provides a true four-wire resistance measurement independent of the connection quality at the current terminals, enabling traceable current calibration at amplitudes up to and beyond 100 A
Related Products of the BWB Series AEC-Q200 Four-Terminal Chip Shunt Resistors
Model: TCS8536
Resistor type: AEC-Q200 E-beam
Description: E-beam welded shunt
Power Rating: 36W
Rated Current: 600~1200A
Resistance (Ω): 0.1m, 0.05m, 0.025m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 100
Model: TCS8440T
Resistor type: AEC-Q200 E-beam
Description: E-beam welded shunt
Power Rating: 36W
Rated Current: 840A
Resistance (Ω): 0.05m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 100
Model: ECS
Resistor type: AEC-Q200
Description: Chip shunt
Power Rating: 1W~15W
Resistance (Ω): 0.2~10m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 100-200
Model: TCS
Resistor type: AEC-Q200 E-beam
Description: Shunt
Power Rating: 12W~36W
Rated Current: 200~350A
Resistance (Ω): 0.05~0.5m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 100
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.
