Analysis
Front-End Measurement ICs for Low-End, Single-Phase Energy Meters
STMicroelectronics has 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, provides electronic meter manufacturers with a complete, cost-effective series of power-metering chips specifically designed for low-end applications.
FullAnalog 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.