CS227 Series High Power Precision Shunt Resistors
Package — TO-227 / SOT-227 compatible housing for direct heatsink mounting
Power Rating — 25W rated power on heatsink
Resistance Range — 1mΩ to 5mΩ
Rated Current — 158A maximum
Tolerance Options — ±1%, ±2%, and ±5%
TCR — ±50ppm/°C maximum
Construction — High power precision metal alloy element
What are the CS227 Series High Power Precision Shunt Resistors?
The CS227 is a high power precision shunt resistor designed for accurate current sensing in demanding industrial and power electronics applications. Built around a metal alloy resistive element housed in the industry-standard TO-227 (SOT-227) package, the CS227 delivers a rated power of 25W with direct heatsink mounting, enabling compact high-current measurement solutions without sacrificing thermal performance. The flat-base housing provides efficient thermal coupling to an external heatsink, keeping element temperatures within safe operating limits even under sustained high-current conditions.
The resistance range spans 1mΩ to 5mΩ, covering the low-resistance, high-current measurement requirements typical of motor drives, battery management systems, and power conversion equipment. Three tolerance grades are available — ±1%, ±2%, and ±5% — allowing designers to select the precision appropriate to their application, from demanding closed-loop control to general-purpose overcurrent monitoring. The temperature coefficient of resistance is specified at a maximum of ±50ppm/°C, ensuring that measurement accuracy is maintained across the operating temperature range without the need for external compensation circuitry.
A defining feature of the CS227 is its rated current capacity of up to 158A, which is achieved through the combination of a low-resistance metal alloy element and the superior thermal management afforded by the TO-227 package geometry. The four-terminal (Kelvin) connection approach inherent to the shunt resistor architecture eliminates lead resistance from the measurement path, ensuring that the voltage sensed across the sense terminals accurately reflects the current through the device rather than the parasitic resistance of the current-carrying conductors. This construction makes the CS227 well suited to precision power metering, battery state-of-charge estimation, and any application where accurate knowledge of load current is critical to system safety or efficiency.
CS227 Series High Power Precision Shunt Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
Model: CS227
Resistor type: Current Sensing
Description: High power shunt
Power Rating: 25W
Rated Current: 158A max.
Resistance (Ω): 1m~5m
Tolerance (%): ±1, ±2, ±5
TCR (ppm/C): 50 max.
Applications of the CS227 Series High Power Precision Shunt Resistors
Where RARA current sensing resistors are deployed in the field.
Motor drive and variable-speed drive circuits — phase current measurement and overcurrent protection
Battery management systems — cell current monitoring for state-of-charge and state-of-health estimation
On-board chargers and DC-DC converters — input and output current sensing for regulation and protection
Inverter and converter control loops — closed-loop current feedback for precision power control
Electric vehicle powertrains — high-current traction inverter and charging system monitoring
Uninterruptible power supplies — load current measurement and battery charge/discharge management
Industrial power supplies and rectifiers — precision current metering and fault detection
Renewable energy systems — solar inverter and wind converter current sensing
Welding and plasma cutting equipment — high-current process monitoring and control
Test and measurement equipment — precision current reference and high-current load simulation
Related Products of the CS227 Series High Power Precision Shunt Resistors
Model: LT
Resistor type: Current sensing
Description: High power precision
Rated Current: 50A~500A
Resistance (Ω): 0.2m~2m
Tolerance (%): ±0.1, ±0.5, ±1
TCR (ppm/C): 30
Model: HPS
Resistor type: Current sensing
Description: High power precision
Power Rating: 250W
Rated Current: 387A max.
Resistance (Ω): 1m~100m
Tolerance (%): ±0.05, ±0.1, ±0.5, ±1
TCR (ppm/C): 3, 5, 10
Model: UHPS
Resistor type: Current sensing
Description: Ultra high power precision
Power Rating: 100W
Rated Current: 707A max.
Resistance (Ω): 0.2m~1m
Tolerance (%): ±0.05, ±0.1, ±0.5, ±1
TCR (ppm/C): 3, 5, 10
Model: PSS
Resistor type: Current sensing
Description: High power precision
Power Rating: 100W
Rated Current: 1400A max.
Resistance (Ω): 50u~1m
Tolerance (%): ±0.1, ±0.5, ±1
TCR (ppm/C): 3, 5, 10
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.
