Energy Measurement IC And Reference Design Eye Power Meters

Debuting as a team, the MCP3909 energy-measurement IC and 3-phase energy-meter reference design forecast faster development times for power-meter applications. The chip integrates 16-bit delta-sigma a/d converters that are accessible through its SPI, while simultaneously providing a pulse output with a frequency proportional to the active-power calculation. It specifies a typical measurement error of 0.1%, dynamic range of 1,000:1, and a power consumption of 4 mA. The reference design includes three MCP3909 chips, plus PIC18F2520 and PIC18F4550 microcontrollers. The PIC18F2520 performs all power calculations, while the PIC18F4550 provides a USB interface. A software package that comes with the design enables meter calibration and the ability to read active/apparent power, RMS current, and RMS voltage. Available in a 24-pin SSOP, price for the MCP3909 is $1.51 each/10,000 and for the reference design (Part # MCP3909RD-3PH1) is $175. MICROCHIP TECHNOLOGY INC., Chandler, AZ. (888) 628-6247.