Front-End Measurement ICs for Low-End, Single-Phase Energy Meters

Fully compliant with specifications for single-phase, class 0.5 static meters, the new STPM1x provides fast and easy digital calibration at only one point over the whole current range, which allows a drastic reduction in manufacturing costs when compared to hardware calibration made using a resistor network. 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.



In the digital part of the device, the hardwired Digital Signal Processor uses innovative, ripple-free computation algorithms to calculate the amount of consummated active energy, thus considerably reducing the meter’s calibration time. In addition, 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 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.