Chipset boosts flexibility and accuracy of smart meters

Pietro Menniti, group vice president and general manager, Industrial and Power Conversion Division, described the chipset as an 'important milestone'. "The new STPMC1 and STPMS1/S2 chips, launched today, support a new modular approach that will offer greater accuracy and reduced costs in the development of leading edge 'poly phase' smart meters for industrial applications," he said. The devices support 50-60Hz IEC and ANSI standards for up to 0.2-class ac Watt meters. The STMPC1 metrology IC, which has five input channels, 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 device can be configured and calibrated for any international distribution standard. Both devices are dual channel delta sigma modulators that convert analogue current and voltage values from each phase and transmit digital data to the STPMC1. According to ST, they can be placed very close to the current sensor to avoid long analogue tracks and high noise capture. The STPMS1 has a first order modulator, while the STPMS2 has a second order modulator designed to deliver enhanced accuracy.