AD7714 Analog Devices, AD7714 Datasheet - Page 35

• Manufacturer Part Number: AD7714
• Manufacturer: Analog Devices

Specifications of AD7714

• Resolution (bits): 24bit
• # Chan: 5
• Sample Rate: 19.2kSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip,Diff-Uni
• Ain Range: (2Vref/PGA Gain) p-p,Uni (Vref)/(PGA Gain)
• Adc Architecture: Sigma-Delta
• Pkg Type: DIP,SOIC,SOP

REV. C
Temperature Measurement
Another application area for the AD7714 is in temperature
measurement. Figure 13 outlines a connection from a thermo-
couple to the AD7714. In this application, the AD7714 is oper-
ated in its buffered mode to allow large decoupling capacitors
on the front end to eliminate any noise pickup which there may
THERMOCOUPLE
+V
JUNCTION
AD780
IN
GND
+5V
V
OUT
R
R
Figure 13. Thermocouple Measurement Using the AD7714
C
REF IN (+)
REF IN (–)
C
AGND
AIN2
AIN1
AIN3
AIN4
AIN5
AIN6
AGND
AV
+5V
AV
DD
DGND
DD
1 A
1 A
BUFFER
DV
DD
BUFFER
DV
–35–
SERIAL INTERFACE
DD
A = 1–128
PGA
have been in the thermocouple leads. When the AD7714 is
operated in buffered mode, it has a reduced common-mode
range. In order to place the differential voltage from the thermo-
couple on a suitable common-mode voltage, the AIN2 input of
the AD7714 is biased up at the reference voltage, +2.5 V.
DOUT
REGISTER BANK
AUTO-ZEROED
CHARGE BALANCING A/D
MODULATOR
DIN
CONVERTER
CS
GENERATION
AD7714
CLOCK
SCLK
DIGITAL
FILTER
MCLK OUT
MCLK IN
STANDBY
SYNC
RESET
DRDY
POL
AD7714
2