Current Sense Resistor

Current sense resistors, also known as shunt resistors, are low-value components used to convert current into a small, proportional voltage while minimizing power loss. Current sense resistors are available with values below 1mΩ and current ratings exceeding 100A. For best measurement accuracy, these components can be connected using four connections: two for the current path and two for voltage sensing. Four-terminal resistor designs facilitate this Kelvin sensing configuration.

Current-sense resistors are available in a variety of shapes and sizes and are widely used to measure current in automotive, power control, and industrial systems. When using very low-value resistors of a few milliohms or less, solder resistance can represent a significant portion of the sense element resistance and introduce measurement errors. High-accuracy applications often use 4-terminal resistors and Kelvin sensing to minimize these errors. The size and design of the resistor pads also play an important role in achieving accurate measurements, particularly when measuring high currents.

Current sensing resistors are available in miniature sizes down to 01005, power ratings up to 3W, high-precision configurations, and low TCR options. Metal technologies including metal foil, metal strip, and welded constructions are combined with thin-film and thick-film technologies to provide a wide range of current sensing solutions. Available resistance values can range from approximately 0.2mΩ to 10Ω, with resistance values and power ratings selected according to application requirements.

Current Sense Resistors: Typical applications include current sensing and snubber circuits in power supplies and electric motor control systems, including electric welding equipment, heaters, power steering systems, and other industrial and automotive applications.

Current Sense Resistor Types