ST’s poly-phase chipset, based on the STPMC1 and STPMS2, represents the first modular solution for metering systems.
The STPMC1 works as an energy calculator designed for effective energy measurement in power-line systems. Used in combination with one or more STPMS2 IC smart sensors, it implements all the functions needed in poly-phase energy meters.
The STPMS2 smart sensor is a dual second-order sigma delta modulator with embedded programmable gain amplifier (PGA). It is highly configurable through hardware pins on the SPI port. The chipset approach allows the A/D conversion (STPMS2) to be positioned very close to the current transducers, so minimizing noise capture from the analog tracks. Once converted, the sigma delta streaming of voltage and current are multiplexed and transferred through a single-wire data line to a dedicated DSP inside the STPMC1.
Wide sensor support, SPI interface, tamper proofing by neutral current, and temperature and magnetic field monitoring make this the ideal solution for multi-purpose, high-performance metering systems.
In particular, the modular architecture allows digitally fully-isolated implementations even using low-cost, tamper-free shunt transducers.
- Computation of active and reactive wideband and fundamental harmonic energies
- Ripple-free energy calculation algorithm
- 112 configuration and calibration bits
- Neutral current, temperature and magnetic field monitoring
- Two 2nd order sigma delta modulators for voltage and current
- 0.1% accuracy in 1:5000 range (STPMS2)
- 0.5% accuracy in 1:10000 range (STPMS2)
Complies with IEC 62052-11/62053-21/62053-22/62053-23, ANSI C12.1-2001/ C12.10-1997/C12.20-2002 standards