AD7739 Analog Devices, AD7739 Datasheet - Page 9

• Manufacturer Part Number: AD7739
• Description: 8-Channel, 4 kHz, 24-Bit Sigma-Delta A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7739

• Resolution (bits): 24bit
• # Chan: 8
• Sample Rate: 3.05MSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip,Diff-Uni,SE-Bip,SE-Uni
• Ain Range: Bip 0.625,Bip 1.25,Bip 2.5V,Uni 0.625,Uni 1.25,Uni 2.5V
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

TYPICAL PERFORMANCE CHARACTERISTICS
±1.25 V, Conversion Time 397 µs, Chopping Enabled, MCLK = 6.144 MHz
Figure 7. Typical FFT Plot; Input Sine Wave 183 Hz,1.2 V Peak, AIN Range
–100
–120
–140
–160
–180
–20
–40
–60
–80
25
24
23
22
21
20
19
18
17
16
25
24
23
22
21
20
19
18
17
16
0
Figure 6. No Missing Codes Performance, Chopping Disabled
Figure 5. No Missing Codes Performance, Chopping Enabled
0
5
5
6
6
200
CHOP = 1
CHOP = 0
THD = 110dB
7
7
400
8
8
INPUT FREQUENCY (Hz)
FILTER WORD
FILTER WORD
9
9
600
10
10
800
11
11
12
12
1000
13
13
1200
14
14
1400
15
15
03742-0-005
03742-0-006
03742-0-007
Rev. 0 | Page 9 of 32
Figure 8. Typical Effective and Peak-to-Peak Resolution; AIN Voltage = 0 V,
Figure 9. Typical Effective and Peak-to-Peak Resolution; AIN Voltage = 0 V,
±1.25 V, Conversion Time 397 µs, Chopping Enabled, MCLK = 6.144 MHz
Figure 10. Typical Common-Mode Rejection vs. AIN Voltage; AIN Range
120
110
100
90
80
70
60
24
22
20
18
16
14
12
10
24
22
20
18
16
14
12
10
8
8
–1.5
AIN Range ±1.25 V, Chopping Disabled, MCLK = 6.144 MHz
0
0
AIN Range ±1.25 V, Chopping Enabled, MCLK = 6.144 MHz
CHOP = 1
CHOP = 0
CHOP = 1
2
2
–1.0
AIN DIFFERENTIAL VOLTAGE (V)
4
4
OUTPUT DATA RATE (kHz)
OUTPUT DATA RATE (kHz)
p-p
p-p
–0.5
6
6
EFFECTIVE (rms)
EFFECTIVE (rms)
8
8
0
10
10
0.5
12
12
1.0
14
14
AD7739
1.5
16
16
03742-0-008
03742-0-009
03742-0-010