Data Sheet
AD5940
2-wire conductivity sensor. The pH measurement indicates the
acidity or alkalinity of the solution and uses an external amplifier
for buffering purposes before conversion by the ADC.
SMART WATER/LIQUID QUALITY AFE
The features and flexibility of the AD5940 make the device ideal
for water analysis applications. These applications typically
measure pH, conductivity, oxidation/reduction, and temperature.
Figure 54 shows a simplified version of the AD5940 configured
to satisfy these measurement needs. The high power PA loop
can be used for the conductivity measurement. Figure 54 shows a
In this application, as shown in Figure 54, the data FIFO and
AFE sequence lend themselves to autonomous,
preprogrammed, smart water measurements.
WAVEFORM
GENERATOR
GAIN
HSDAC
CE0
EXCITATION
BUFFER
RE0
V
SEQUENCER
BIAS
LPDAC0
V
ZERO
CONDUCTIVITY
16MHz
OSC
V
ZERO
+
HSTIA
HSTIA
AIN0
–
ADC/
800kHz
FIFO
pH LEVEL
ADA469x
AIN1
OXIDATION/
REDUCTION
AD5940
Figure 54. Typical Water Analysis Application Using the AD5940
Rev. 0 | Page 129 of 130
ADI [ ADI ]
