Enabling utility companies to improve billing by accurately measuring down to extremely low power levels, the STPM32, STPM33 and STPM34 ICs have been unveiled by STMicroelectronics. Meters which incorporate these devices will help utilities minimise revenue losses and ensure consistent billing by keeping the meter accuracy down to just a few milliamps - comparable to the current drawn by an LED television in standby.
While meters are highly accurate at current levels typically down to 50mA, today’s home electronics and appliances offer ever-lower standby power. Errors at lower currents can bring about up to Megawatt-hours of lost billings across a large customer base for utilities.
The STPM3 devices also enable the development of more economical meters that help utilities reduce their operating costs. The chips can offload the meter’s host processor to simplify software by performing power-quality calculations on-chip, including RMS voltage and current measurement, apparent-energy computation and under-voltage/over-voltage detection. The STPM33 and STPM34 feature neutral-phase tamper detection which further simplifies the design and enhances system security. The STPM34 can also calculate apparent power in single- and multi-phase systems.
By integrating key functions, such as a voltage regulator, a temperature-compensated voltage reference supporting long-term accuracy and a SPI/UART host connection allowing low-cost isolation for immunity to DC magnetic fields, the smart-meter ICs simplify hardware design, saving external components and PCB size.
Providing two, three or four independent channels respectively, for single- and poly-phase AC applications, the STPM32, STPM33 and STPM34 devices comply with applicable IEC, ANSI and SGCC standards and requirements.
Pricing for the STPM32, STPM33 and STPM34 smart meter ICs starts below $1 each in 1,000 unit quantities.