Abstract

Accurate current measurement is a basic requirement in motor control, power management, and energy monitoring systems. Among traditional sensing techniques such as current transformers (CTs), current shunts provide a direct measurement approach that is the most reliable and cost-effective.

Current shunt resistors of few µΩ or mΩ are generally used for current sensing. However, voltage measurements using low ohmic values in the range of few µΩ have a higher probability of being affected by PCB trace resistance, Temperature Coefficient of Resistance (TCR), and solder resistance. This effect becomes more challenging when current sense resistors are mounted in parallel. This application note will discuss best layout practices and considerations for designing shunts in parallel.