Microchip’s MCP3909 energy measurement IC is highly accurate and combines low power consumption with an SPI interface and active power-pulse output, making it adaptable to a wide variety of meter designs. Together with the MCP3909 3-Phase Energy Meter Reference Design, the IC enables designers to develop and bring meter designs to market quickly.
The MCP3909 IC has two 16-bit delta-sigma Analog-to-Digital Converters (ADCs) onboard that can be accessed through its SPI interface, while simultaneously providing a pulse output with a frequency proportional to the active-power calculation. The simultaneous output of data makes the IC flexible and easy to use, as well as adaptable to a variety of meter requirements. Additionally, with its very low, 0.1% typical measurement error over a 1000:1 dynamic range, the MCP3909 IC easily fits into meter applications requiring high accuracy. Its extremely low supply current of only 4 mA makes it suitable for many single- and three-phase energy meter designs, and helps customers remain within their power budget.
The MCP3909 3-Phase Energy Meter Reference Design (Part# MCP3909RD-3PH1) includes three MCP3909 ICs, plus a PIC18F2520 and a PIC18F4550 microcontroller. The PIC18F2520 performs all power calculations in the reference design, while the PIC18F4550 provides a USB interface to desktop software. The software package that comes with the reference design enables meter calibration and the ability to read active and apparent power, as well as RMS current and RMS voltage. The reference design is expected to be available for purchase at a price of $175 each.
The MCP3909 energy-measurement IC is well suited for a variety of single- and three-phase industrial and consumer energy meters. The IC is available in a 24-pin SSOP package for $1.51 each in 10,000-unit quantities.
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