High-Power Current Sense Resistors Product Extension - CSM2F Series

Bourns' model CSM2F series is an extension of the current sense resistor family with four different footprint sizes which include 6918, 7036, 8518, and 8536. Current sense resistors are growing in popularity due to their high measurement accuracy and relatively low cost compared to other technologies. This product series complements Bourns’ other circuit conditioning components, such as power inductors and rectifier diodes. These models come with either two or three tin-plated copper pins. Two pins are riveted to the voltage test points of the shunt resistor in order to measure the voltage drop on the resistive element, which is proportional to the current flow through the resistor. The optional third pin connects to the ground side of the circuit. For two-pin designs, the current used by the sensor device flows through the ground side pin and causes a voltage drop between the PCB connection and the resistor, which can result in a sensing error. Three-pin designs reduce the sensing error by carrying the ground current on a separate path from the sensing circuit.

The CSM2F series features resistance values ranging from as low as 25 µΩ up to 200 µΩ, with permanent power ratings of up to 50 W, a continuous current of up to 1,414 amps and the ability to handle high pulse power ratings. The metal alloy current sensing element enables thermal EMF as low as 0.25 µV/K and low TCRs of ±50 PPM/°C in the +20°C to +60°C temperature range.

Resources

• Optimizing Battery Management in High-Voltage Energy Storage System - White Paper
• Bourns Power and Current Sense Resistor - Selection Guide
• Using Current Sense Resistors for Accurate Current Measurement - Application Note