Single phase bi-directional active and reactive energy metering IC with serial SPI interface


Single phase micro-controller based kWh and kvar meter


  • Performs bi-directional active and reactive power/energy measurement
  • RMS Voltage and frequency measurement
  • SPI communication
  • Meets the IEC 61036 Specification requirements for Class 1 AC Watt hour meters
  • Meets the IEC 1268 Specification requirements for VAR hour meters
  • Total power consumption rating below 25m
  • Adaptable to different current sensor technologies
  • Operates over a wide temperature range
  • Precision voltage reference on-chip


The SAMES SA9903B is a single phase bi-directional energy/power metering integrated circuit that performs measurement of active and reactive power, mains voltage and mains frequency. The SA9903B is pin compatible to the SA9603B. New features include, RMS mains voltage and accurate reactive power measurements. Measured values for active and reactive energy, the mains voltage and frequency are accessible through a SPI bus from 24 bit registers. This innovative universal single phase power/energy metering integrated circuit is ideally suited for energy calculations in applications such as electricity dispensing systems (ED’s), residential municipal metering and factory energy metering and control. The SA9903B integrated circuit is available in a 20 pin small outline (SOIC-20) RoHS compliant package.