New Energy Measurement Analog Front Ends for Single-Phase Smart Meters
Microchip Releases New MCP3912 and MCP3919 Analog Front Ends with 24-bit A/D Accuracy
Microchip has announced the completion of its high-accuracy, 1-8 channel, single and poly-phase MCP391X energy-measurement Analog Front End (AFE) family.
The new MCP3919 and MCP3912 members integrate three and four channels of 24-bit, delta-sigma Analog-to-Digital Conversion (ADC), respectively,
with industry-leading accuracy of 93.5 dB SINAD, -107 dB THD and 112 dB SFDR for precise signal acquisition and higher-performing end products.
These are the optimal numbers of channels for single-phase energy meters with neutral monitoring (3-channel);
or single-phase, three-wire energy meters (4-channel).
The high level of integration on the new AFEs also includes a low-drift voltage reference, programmable gain amplifiers,
phase-delay compensation and cyclic redundancy check (CRC).
As the energy-metering infrastructure is being upgraded worldwide, designers are demanding increased AFE accuracy and integration 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, electronic circuit breakers, smart power strips and other data-acquisition products in the industrial, commercial and consumer markets. Microchip's newest AFEs improve application performance with their industry-leading accuracy, high integration and optimal number of channels for single-phase energy measurement. Additionally, the high AFE accuracy facilitates energy-meter calibration, which reduces production costs.
“These new energy-measurement AFEs complete our high-accuracy family,” said Bryan J. Liddiard, marketing vice president of Microchips Analog and Interface Products Division. ' “Now designers have a single source for any single-phase or poly-phase application.”
Features of the MCP3919 Three Channel Analog-Front-End
- Three Synchronous Sampling 24-bit Delta-Sigma A/D Converters
- 93.5 dB SINAD, -107 dBc THD, 112 dBFS SFDR
- Enables 0.1% Typical Active Power Measurement Error over a 10,000:1 Dynamic Range
- 2.7V - 3.6V AVDD, DVDD
- Programmable Data Rate up to 125 ksps
- 4 MHz Maximum Sampling Frequency
- Advanced Security Features
- 16-Bit CRC Checksum and Interrupt Alert
- Register Map Lock
- Oversampling Ratio up to 4096
- Ultra Low Power Shutdown Mode with <10 µA
- -122 dB Crosstalk between the Two Channels
- Low Drift 1.2V Internal Voltage Reference: 9 ppm/°C
- Differential Voltage Reference Input Pins
- High Gain PGA on Each Channel (up to 32V/V)
- Phase Delay Compensation with 1 µs Time Resolution
- Separate Data Ready Pin for Easy Synchronization
- Individual 24-bit Digital Offset and Gain Error Correction for Each Channel
- Flexible serial interface that includes both SPI and a simple 2-wire interface ideal for polyphase shunt energy meters
- Continuous Read/Write Modes for Minimum Communication
More information on the MCP3919 Analog-Front-End can be found on the Microchip Web site
Microchip MCP3919 product page
Note: The Microchip name and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A and other countries. All other trademarks mentioned herein are the property of their respective companies.
The company's Web site address is www.microchip.com
[Reprinted with kind permission from Microchip Corporation - Release Date, 4th November, 2014]