Shown here is a unique application that takes advantage of the LTC2974’s voltage, current and temperature monitoring capabilities. In many multi-rail systems, there is a need to accurately measure current, where using an external shunt is not an option because it introduces too much power loss or makes the converters too expensive. A lossless alternative is to measure the average voltage drop across the direct current resistance (or DCR) of an inductor, which saves component count and simplifies board layout. However, one significant drawback of the DCR method is the strong temperature dependence of the inductor resistance and the difficulty in measuring the exact inductor core temperature. Without proper temperature compensation, a change of inductor temperature of only 1°C corresponds to approximately 0.39% of current measurement error. To make matters worse, inductor self-heating of tens of degrees can be observed at high loading levels. The LTC2974 can compensate for these effects by allowing the designer to input the thermal resistance and thermal time constant of the inductor being used. The result is a DCR temperature compensated current measurement scheme that, when calibrated, achieves accuracy better than ±0.25% across the full temperature and load current range.