AD7714
Data Acquisition
from a single +3 V or +5 V supply provided that the input sig-
nals to the AD7714’s analog inputs are all of positive polarity.
The low power operation of the AD7714 ensures that very little
power has to be brought across the isolation barrier. Figure 15
shows the AD7714 in an isolated data acquisition system.
The AD7714 with its three differential channels (or five pseudo-
differential channels) is suited to low bandwidth, high resolution
data acquisition systems. In addition, the three-wire digital
interface allows this data acquisition front end to be isolated
with just three optoisolators. The entire system can be operated
+5V
2
DV
AV
DD
DD
DD
AV
AD7714
1A
CHARGE BALANCING A/D
STANDBY
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
IN1+
IN1–
IN2+
IN2–
IN3+
IN3–
CONVERTER
AUTO-ZEROED
DIGITAL
FILTER
SYNC
⌺⌬
PGA
A = 1–128
BUFFER
MODULATOR
MCLK IN
CLOCK
GENERATION
1A
+5V
SERIAL INTERFACE
MCLK OUT
AGND
REGISTER BANK
+V
IN
REF IN (+)
RESET
V
OUT
AD780
GND
DRDY
REF IN (–)
AGND
POL
DGND
DOUT
DIN
SCLK
BUFFER
CS
DV
DD
OPTO-ISOLATORS
MICROCONTROLLER
Figure 15. Data Acquisition System Using the AD7714
REV. C
–37–
ADI [ ADI ]
