STMicroelectronics introduced a family of energy-metering ICs that incorporate all of the core circuitry necessary to implement a complete meter system without requiring any other active component. The STPM1x family, measuring active energy as pulse frequency output and featuring fast digital calibration. Fully compliant with specifications for single-phase, class 0.5 static meters, the STPM1x provides digital calibration at only one point over the whole current range.

The mixed-signal IC is designed for effective measurement of active energy in a power-line system using a wide variety of current sensors such as shunts, current transformers, and Rogowsky coils. Analog blocks within the STPM1x include preamplifiers for signal conditioning, Analog-to-Digital converters, and low-drop voltage regulators to supply the circuitry. The active energy is available through complementary pulsed outputs that enable an easier energy measurement while directly driving stepper-motor counters in low-end applications. The device is configured and calibrated through a serial port, which exploits the One-Time Programmable (OTP) cells for permanently storing calibration parameters, hence preventing any subsequent tamper. Offered in the TSSOP20 ECOPACK package, the STPM1x is available in volume now at a price of US$1.4 for quantities of 1,000.