Energy-measurement analogue front ends offer high accuracy

February 24, 2014 // By Graham Prophet
For use in 3-phase smart meters and multiple-load power monitoring, these AFEs integrate up to eight 24-bit ADCs with programmable data rate and specifications of 94.5 dB SINAD, -106.5 dB THD and 112 dB SFDR.

Microchip Technology has announced its next-generation family of energy-measurement Analog Front Ends (AFEs); the MCP3913 and MCP3914 integrate six and eight 24-bit, delta-sigma Analogue-to-Digital Converters (ADCs), respectively, with 94.5 dB SINAD, -106.5 dB THD and 112 dB SFDR for high-accuracy signal acquisition and higher-performing end products. The MCP3914’s two extra ADCs enable the monitoring of more sensors with one chip, lowering cost and size. Additionally, the programmable data rate of up to 125 ksamples/sec with low-power modes allows designers to scale down for better power consumption or to use higher data rates for advanced signal analysis, such as calculating harmonic content. These AFEs also feature a CRC-16 checksum and register-map lock, for increased robustness.

As the energy-metering infrastructure is being upgraded worldwide, designers are demanding, Microchip says, increased AFE accuracy, performance and flexibility to develop the latest generation of smart meters. These features are also required by the designers of advanced power-monitoring systems for applications such as server power supplies and power distribution units, uninterruptible power supplies, smart power strips and data-acquisition products in the industrial and commercial markets.

Microchip also announced two new tools to aid in the development of energy systems using these AFEs. The MCP3913 Evaluation Board (ADM00522) and MCP3914 Evaluation Board (ADM00523) each cost $99.99. MCP3913 and MCP3914 AFEs cost from $3.04 (5,000) in 40-pin uQFN packages, and the MCP3913 adds a 28-pin SSOP package option.