Rethinking Current Measurement: Why ESL Disrupts System Correlation

Modern systems exhibit inconsistent measurement results, especially when comparing simulation, bench validation, and real-world system performance. Engineers often see a lack of correlation between simulation, bench measurements, and real system performance, even when following established best practices. This is partly due to how equivalent series inductance (ESL) is measured within a system. Engineers need to measure high speed current from DC and all the up to gigahertz frequencies without interfering with the circuit. While there are methods to compensate for ESL, such as increasing bandwidth or canceling it within the measurement, these techniques do not remove the sensing element’s physical interaction with the circuit. These techniques can mask the underlying error rather than eliminate it.