Energy metering applications simplified with smart power technology

STMicroelectronics’ STPM01 addresses a wide range of electricity metering requirements, operating as a standalone power meterin the simplest low-end equipment or as a peripheral in sophisticated microprocessor- based meters that support functions suchas remote metering, reactive power measurement, multiple tariffs and tamper detection. Jointly developed by STMicro and Iskraemeco, theSTPM01 is a standard device modified from an ASIC solution built for Iskraemeco using ST’s BCD6 smart powertechnology, allowing all of the necessary analog, digital and power circuits to be integrated on a single chip.

The major blocks include analog signal conditioning, two ADCs, a hardwired dedicated DSP, an SPI interface to an external MCU, a block of 56 OTP bits for calibration and configuration, a voltage-tofrequency converter to drivea stepper motor display in low-end applications, and two current-limited, low-drop voltage regulators to supply the analog (3V) and digital (1.5) circuitry.

The STPM01 offers high performance in terms of accuracy, allowing full compliance with the IEC62052-11 and IEC62053- 2X specifications for singlephase class 0.5 wattmeters, while a synchronization pin also supports three-phase metering applications. The device operates over a wide range of mains voltage (40 to 300VRMS) and line frequency (45 to 65Hz), and can measure up to 200ARMS.

STMicroelectronics,