STMicroelectronics STPM33/34 Single Phase Metering ICs are an ASSP family designed for high accuracy measurement of power and energies in power line systems using the Rogowski coil, current transformer or shunt current sensors. These provide instantaneous voltage and current waveforms and calculates RMS values of voltage and currents, active, reactive and apparent power and energies. The STPM33/34 is a mixed signal IC family consisting of an analog and a digital section. The analog section consists of up to two programmable gain low-noise low-offset amplifiers and up to four 2nd order 24-bit sigma-delta ADCs, two bandgap voltage references with independent temperature compensation, a low drop voltage regulator and DC buffers. The digital section consists of digital filtering stage, a hardwired DSP, DFE to the input and a serial communication interface (UART or SPI). These are fully configurable and allows a fast digital system calibration in a single point over the entire current dynamic range.