ADE7903 Datasheet, PDF (1/28 Pages) Analog Devices – 3-Channel, Sigma-Delta ADC with SPI

Data Sheet
3-Channel, Sigma-Delta ADC with SPI
ADE7903
FEATURES
One (ADE7903) 24-bit, Σ-Δ ADC (simultaneously sampling
with three ADE7912/ADE7913 ADCs)
On-chip temperature sensor
4-wire SPI serial interface
Standalone 24-bit, Σ-Δ ADC
Up to four ADE7903 and ADE7912/ADE7913 devices clocked
from a single crystal or an external clock
Synchronization of multiple ADE7903 and ADE7912/ADE7913
devices
±31.25 mV peak input range for current channel
±500 mV peak input range for voltage channels
Single 3.3 V supply
20-lead, wide body SOIC package
Operating temperature: −40°C to +85°C
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)
GENERAL DESCRIPTION
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
TYPICAL APPLICATION CIRCUIT
PHASE PHASE PHASE
NEUTRAL
A
B
C
ISOLATION
BARRIER
LOAD
V1P
3.3V
VM
IM _{PHASE A}
ADE7912/
IP ^ADE7913
V2P
GND_{ISO_A}
GND_MCU
V1P
3.3V
VM
IM _{PHASE B}
ADE7912/
IP ^ADE7913
V2P
GND_{ISO_B}
GND_MCU
V1P
3.3V
VM
IM _{PHASE C}
ADE7912/
IP ^ADE7913
V2P
GND_{ISO_C}
GND_MCU
V1P
VM
IM
NEUTRAL
LINE
ADE7903
IP
V2P
3.3V
GND_MCU
Figure 1.
3.3V
GND_MCU
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.
Rev. 0
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