Chandler, Ariz.—In a dual announcement, Microchip Technology has released its MCP3905 and MCP3906 stand-alone energy-measurement integrated circuit (ICs), and also launched its on-line Utility Meter Design Center to provide designers with the tools and resources they need to create accurate and low-cost utility meter solutions for a wide range of applications.
The MCP3905/6 analog front ends for measuring average and instantaneous real power, combined with the company's PIC family of microcontrollers, form the core of a single-phase power meter for residential and industrial applications. The chips each integrate two 16-bit delta-sigma analog-to-digital converters (ADCs), an internal voltage reference, plus all of the digital circuitry needed to calculate average and instantaneous real power from its voltage and current input channels. It delivers a frequency output proportional to real power, and a high-frequency output proportional to instantaneous power for meter calibration. The MCP3905 features a programmable gain amplifier (PGA) with a maximum gain of 16. For energy meters requiring higher accuracy, the MCP3906 has a maximum gain of 32.
The ICs provide high accuracy, touting a 0.1 percent typical measurement error over a 500:1 dynamic range for the MCP3905, and a 1000:1 range for the MCP3906. An on-chip voltage reference minimizes measurement drift during the life of the energy meter.
Other features include direct drive for both mechanical counters and two-phase stepper motors, a tamper output pin for negative power indication, and low power operation: Current draw is just 4 mA. The chips are rated for operation over an industrial temperature range of -40 to +85°C.
The company's new online design center at www.microchip.com/meter facilitates quick and cost-effective designs. "Microchip continues to see a growing opportunity in electronic metering applications worldwide, and our new Utility Meter Design Center helps simplify the metering design process and speed the design cycle for our engineering customers," said Bryan Liddiard, vice president of marketing. "(We offer) innovative solutions that address critical design features, such as accurate power measaurement, low-cost display interfaces, low power consumption, remote communication, and billing." These designs encompass energy, water, gas, and heat metering.
The MCP3505/6 datasheet is available at www.microchip.com/MCP390X The MCP3905 and MCP3906 (24-pin SSOP package) are priced at $1.58 and $1.85 each, respectively, both in 10k quantities. All device packaging is lead (Pb) free. The company also offers its MCP3905/MCP3906 Energy Meter Reference Design Board (Part # MCP3905RD-PM1) and the MCP3905/MCP3906 Energy Meter Evaluation Board
(Part # MCP3905EV). The MCP3905RD-PM1 is priced at $45 and the MCP3905EV is $75.
Microchip Technology, 1-888-MCU-MCHP, www.microchip.com