The STPMS1, also called a smart-sensor device, is an ASSP designed for effective measurement in power line systems utilizing the Rogowski coil, current transformer, or shunt principle. It is used in combination with the STPMC1 programmable poly-phase energy calculator IC, as a building block for single-phase or poly-phase energy meters. The STPMS1 is a mixed signal IC consisting of an analog and a digital section. The analog section consists of a pre-amplifier and two 1storder ΣΔ modulator blocks, band-gap voltage reference, a low-drop voltage regulator, and DC buffers, while the digital section consists of a clock generator and output multiplexer. This device is designed for use in medium resolution measurement applications when single or double inputs must be monitored at the same time.