ADE7912 and ADE7913 Isolated ADC Overview PDF

ADE7912 and ADE7913
Isolated ADC
Overview
The ADE7912 and ADE7913 are fully isolated analog-to-digital converters (ADCs) designed for a variety of
applications. This solution incorporates Analog Devices’ patented iCoupler® and isoPower® technologies to
implement isolated signal transfer and dc-to-dc power conversion across a 5 kV-rated insulation barrier.
This integration enables the use of shunt resistor sensing elements instead of current transformers (CTs),
thereby providing immunity to magnetic field interference and tampering. The use of shunts instead of CTs
also reduces system cost and size.
Features
Applications
• Three 24-bit isolated ADCs: one current channel and two
voltage channels
• Shunt-based polyphase meters
• Integrated isoPower, isolated dc-to-dc converter
• Up to four ADE791x ICs clocked from a single crystal or
an external clock
• On-chip temperature sensor muxed with second
voltage channel
• Power quality monitoring
• Solar inverters
• Process monitoring
• Protective devices
• 4-wire SPI serial interface
• Synchronization between multiple ADE791x ICs
• Isolation rating: 5000 V rms for 1 minute per UL1577,
10,000 V surge
• 20-lead wide body SOIC package with increased 8.3 mm
clearance and creepage
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Functional Block Diagram
ISOLATION
BARRIER
VDDISO
GNDISO
LDO
V2P
VM
V1P
IM
IP
REF
GNDISO
ADE7913
1
2
8
3
5
4
20
POWER
ISOLATION
9
VDD
GND
LDO
TEMP
SENSOR
18
ADC
DATA
ADC
ADC
VREF
10
CLOCK
17
DATA
DATA
ISOLATION
6
7
19
CLOCK
DIGITAL
BLOCK
AND
SPI PORT
16
15
14
13
CS
SCLK
MOSI
MISO
XTAL2
XTAL1
12 CLKOUT/
DREADY
11
GND
General Description
The ADE7912 and ADE7913 feature three 24-bit analog-to-digital converters, each of which provides 70 dB signal-to-noise ratio
over a 3 kHz signal bandwidth. One channel is dedicated to measuring the voltage across a shunt when the shunt is used for
current sensing. Two additional channels are dedicated to measuring voltages, which are usually sensed using resistor dividers.
One of these channels may be used to measure the temperature measurement of the die, using an internal sensor. The ADE7912
is the same as the ADE7913 but it does not include the second voltage measurement.
The ADE7912 and ADE7913 include isoPower, an integrated, isolated dc-to-dc converter. Based on the Analog Devices iCoupler
technology, the dc-to-dc converter provides the regulated power required by the first stage of the ADCs at 3.3 V input supply.
This device eliminates the need for an external dc-to-dc isolation block. The iCoupler chip scale transformer technology is also
used to isolate the logic signals between the first and second stages of the ADC. The result is a small form factor, total isolation
solution.
The ADE7912/ADE7913 contains a bidirectional SPI serial port interface. It provides access to the ADC outputs, configuration,
and status registers for easy interfacing with microcontrollers. The ADE7912/ADE7913 is available in the 20-lead wide body SOIC
Pb-free package with increased creepage.
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