Analog Devices Inc.United States

The ADE7903 is a nonisolated, 3-channel, Σ-Δ analog-to-digital converter (ADC) for the neutral line of polyphase energy metering applications using shunt current sensors. The ADE7903 can also be used for single-phase energy metering and other standalone ADC applications. The ADE7903 features three 24-bit ADCs. The current ADC provides a 67 dBFS signal-to-noise ratio (SNR) over a 3.3 kHz signal bandwidth, whereas the voltage ADCs provide an SNR of 72 dBFS over the same bandwidth. One channel is dedicated to measuring the voltage across a shunt when the shunt is used for current sensing. Up to two additional channels are dedicated to measuring voltages, which are usually sensed using resistor dividers. One voltage channel can be used to measure the temperature of the die via an internal sensor. The ADE7903 includes three channels: one current channel and two voltage channels. Together with the ADE7912 / ADE7913 , the ADE7903 provides a small form factor, 3-phase isolated solution with a neutral measurement. The three phases are isolated with ADE7912 / ADE7913 devices, while the neutral line is not isolated with the ADE7903. The ADE7903 configuration and status registers are accessed via a bidirectional SPI serial port for easy interfacing with microcontrollers. The ADE7903 can be clocked from a crystal or an external clock signal. To minimize the system bill of materials, the master ADE7912 / ADE7913 can drive the clocks of up to three additional ADE7912 / ADE7913 or ADE7903 devices. Multiple ADE7912 / ADE7913 and ADE7903 devices can be synchronized to sample at the same moment and provide coherent outputs. The ADE7903 can also be used individually as a standalone ADC. The ADE7903 is available in a 20-lead, Pb-free, wide body SOIC package. APPLICATIONS 3-phase shunt-based polyphase meters with neutral channel measurement Single-phase meters Power quality monitoring Solar inverters Process monitoring Standalone ADCs Protective devices Isolated sensor interfaces Industrial programmable logic controllers (PLCs)