Metering chips from STMicroelectronics are claimed to offer the industry's most accurate and cost-effective solution for next-generation smart meters. Smart meters operate as a high-accuracy modulator for sensed current and voltage signals and a dedicated metrology processor to calculate energy consumption. Single-phase metering chips integrate these functions in a single component. In three-phase, or poly-phase, smart meters for industrial applications, a modular approach that separates the current and voltage sensing from the metrology section can improve accuracy and economy. The modulator ICs in the sensing circuitry can be mounted closer to the measurement transducers to reduce the effects of noise. The STPMC1 and STPMS1/S2 create a chipset for modular smart meters, supporting 50 to 60Hz IEC and ANSI standards for up to 0.2-class AC Watt meters. The STMPC1 metrology IC has five input channels and accepts measurements from three phases with the option of using the fourth channel for tamper detection or temperature sensing, and the fifth channel to accept magnetic field information from a Hall sensor. The ICs are dual-channel, delta-sigma modulators that convert analogue current and voltage values from each phase and transmit digital data to the STPMC1.
