STPM33 Single-Phase Metering ICs

STPM33 Single-Phase Metering ICs

STMicroelectronics' STPM3x is 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. The STPM3x provides instantaneous voltage and current waveforms and calculates RMS values of voltage and currents, active, reactive and apparent power and energies.

The STPM3x 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 second 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). The STPM3x is fully configurable and allows a fast digital system calibration in a single point over the entire current dynamic range.

Key Features  
  • Active power accuracy:
    • <0.1% error over 5000: 1 dynamic range
    • <0.5% error over 10000: 1 dynamic range
  • Exceeds 50-60 Hz EN 50470-x, IEC 62053-2x, ANSI12.2x standard requirements for AC watt meters
  • Reactive power accuracy:
    • <0.1% error over 2000: 1 dynamic range
  • Dual-mode apparent energy calculation
  • Instantaneous and averaged power
  • RMS and instantaneous voltage and current
  • Under and overvoltage detection (sag and swell) and monitoring
  • Overcurrent detection and monitoring
  • UART and SPI serial interface with programmable CRC polynomial verification
  • Programmable LED and interrupt outputs
  • Four independent 24-bit second order sigma-delta ADCs
  • Two programmable gain chopper stabilized low-noise and low-offset amplifiers
  • Bandwidth 3.6 kHz at -3 dB
  • VCC supply range 3.3 V ±10%
  • Supply current ICC 4 mA (STPM32)
  • Input clock frequency 16 MHz, Xtal or external source
  • Twin precision voltage reference: 1.23 V with independent programmable TC, 10 ppm/°C typ.
  • Internal low drop regulator at 3 V (typ.)
  • QFN packages
  • Operating temperature -40°C~+85°C