Date: 04/10/2012

3-channel A/D converter for energy meter design works with shunt resistor

Analog Devices, Inc., (ADI) has introduced a fully isolated A/D converter designed for polyphase energy metering applications. The ADE7913 3-channel, sigma-delta A/D converter includes ADI’s patented iCoupler and isoPower technologies to implement isolated signal transfer and dc-to-dc power conversion across a 5kV-rated insulation barrier. This allows the use of shunt resistor sensing elements instead of current transformers (CTs), thereby offering immunity to magnetic field interference and tampering. The use of shunts instead of CTs also reduces system cost and size.

“In the past, polyphase meter manufacturers had to decide between CT-based architectures vulnerable to external magnetic fields, or discrete component shunt-based architectures involving excessive complexity and functionality compromises,” said Ronn Kliger, director for the Energy Group, Analog Devices. “Now, with an integrated component incorporating synchronized A/D conversion and galvanic isolation, our customers can develop feature-rich, cost-effective metrology solutions that are completely immune to magnetic interference.”

Features of ADE7913:
1. Three 24-bit isolated A/D converters: one current channel and two voltage channels
2. Integrated isoPower isolated dc-to-dc converter
3. Up to four ADE7913 energy metering ICs synchronously clocked from a single crystal or an external clock
4. On-chip temperature sensor
5. Integrated voltage reference and voltage regulator
6. SPI serial interface

Product Sample availability Channels Price each in 1,000 quantities Package
ADE7913 Now 1 current channel and 2 voltage channels $5.71 20-lead wide body SOIC package with greater than 8mm clearance and creepage
ADE7912 Now 1 current channel and 1 voltage channel $5.42

The EVAL-ADE7913EBZ evaluation board for the ADE7913 is now available at a price of $350.00.

Source: Analog Devices