AD7712 Analog Devices, AD7712 Datasheet - Page 27

• Manufacturer Part Number: AD7712
• Description: CMOS, 24-Bit Sigma-Delta, Signal Conditioning ADC with 2 Analog Input Channels
• Manufacturer: Analog Devices

Specifications of AD7712

• Resolution (bits): 24bit
• # Chan: 2
• Sample Rate: 19.5kSPS
• Interface: Ser
• Analog Input Type: Diff-Bip,Diff-Uni,SE-Bip
• Ain Range: Bip (Vref) x 4,Bip (Vref)/(PGA Gain),Bip 10V,Bip 20V,Uni (Vref) x 4,Uni (Vref)/(PGA Gain),Uni 10V,Uni 20V
• Adc Architecture: Sigma-Delta
• Pkg Type: DIP,SOIC

APPLICATIONS
4–20 mA LOOP
The AD7712’s high level input can be used to measure the
current in 4–20 mA loop applications as shown in Figure 20. In
this case, the system calibration capabilities of the AD7712 can
be used to remove the offset caused by the 4 mA flowing
REV. F
4–20mA
LOOP
COPLANARITY
0.30 (0.0118)
0.10 (0.0039)
Figure 20. 4–20 mA Loop Measurement Using the AD7712
0.10
ANALOG +5V SUPPLY
AIN1(–)
AIN1(+)
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
500
24-Lead Standard Small Outline Package [SOIC]
AIN2
AV
1.27 (0.0500)
1
24
DD
AGND DGND
COMPLIANT TO JEDEC STANDARDS MS-013AD
Dimensions shown in millimeters and (inches)
BSC
ATTENUATION
AV
AD7712
DV
VOLTAGE
DD
DD
15.60 (0.6142)
15.20 (0.5984)
OUTLINE DIMENSIONS
4.5 A
M
U
X
0.51 (0.0201)
0.31 (0.0122)
V
IN (–)
REF
SS
A = 1 – 128
PGA
Wide Body
RFS
(RW-24)
IN (+)
REF
–27–
TFS
REGISTER
2.65 (0.1043)
2.35 (0.0925)
CONTROL
SEATING
PLANE
13
12
CHARGE-BALANCING A/D
AUTO-ZEROED
through the 500 Ω resistor. The AD7712 can handle an input
span as low as 3.2
though the nominal input voltage range for the input is 10 V.
Therefore, the full span of the A/D converter can be used for
measuring the current between 4 mA and 20 mA.
MODE SDATA SCLK
MODULATOR
SERIAL INTERFACE
7.60 (0.2992)
7.40 (0.2913)
V
BIAS
CONVERTER
–
0.33 (0.0130)
0.20 (0.0079)
10.65 (0.4193)
10.00 (0.3937)
GENERATION
2.5V REFERENCE
REGISTER
CLOCK
OUTPUT
REF OUT
DIGITAL
FILTER
8
0
DRDY
0.75 (0.0295)
0.25 (0.0098)
V
A0
REF
1.27 (0.0500)
0.40 (0.0157)
MCLK IN
MCLK OUT
(= 8 V with a V
SYNC
STANDBY
45
REF
of 2.5 V) even
AD7712