AD7291 Analog Devices, AD7291 Datasheet - Page 8

• Manufacturer Part Number: AD7291
• Description: 8-Channel, I2C, 12-Bit SAR ADC with Temperature Sensor
• Manufacturer: Analog Devices

Specifications of AD7291

• Resolution (bits): 12bit
• # Chan: 8
• Sample Rate: 22.2kSPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref)
• Adc Architecture: SAR
• Pkg Type: CSP

AD7291
TYPICAL PERFORMANCE CHARACTERISTICS
–0.2
–0.4
–0.6
–0.8
–1.0
–0.2
–0.4
–0.6
–0.8
–1.0
–100
–120
–20
–40
–60
–80
1.0
0.8
0.6
0.4
0.2
1.0
0.8
0.6
0.4
0.2
0
0
0
0
0
0
T
V
V
V
f
f
S
SCL
V
f
f
f
SNR = 71.209
THD = –81.66
A
DRIVE
REF
DD
S
SCL
IN
DD
= 22.22ksps
= 25°C
= 22.22ksps
= 10kHz
500
500
= 3V
= 400kHz
= V
= 2.5V
= 400kHz
= 3V
DRIVE
2k
1000
1000
Figure 6. Typical ADC DNL
Figure 5. Typical ADC INL
= 3V
Figure 4. Typical FFT
1500
1500
4k
FREQUENCY (Hz)
ADC CODE
ADC CODE
2000
2000
6k
2500
2500
3000
3000
8k
T
V
V
V
f
f
S
SCL
A
3500
DRIVE
REF
DD
3500
= 22.22ksps
= 25°C
= 3V
= 400kHz
= 2.5V
= 3V
10k
4096
4096
Rev. B | Page 8 of 28
11.7
11.6
11.5
11.4
11.3
11.2
–0.2
–0.4
–0.6
–0.8
–1.0
–0.2
–0.4
–0.6
–0.8
–1.0
1.0
0.8
0.6
0.4
0.2
1.0
0.8
0.6
0.4
0.2
0
0
0
0
0
Figure 9. Effective Number of Bits vs. V
T
V
V
f
f
S
SCL
T
V
V
f
f
A
DRIVE
DD
S
SCL
A
= 22.22ksps
DRIVE
DD
= 25°C
= 22.22ksps
= 25°C
= 3V
= 400kHz
= 3V
= 400kHz
0.5
0.5
= 3V
0.5
= 3V
Figure 8. DNL vs. External V
Figure 7. INL vs. External V
EXTERNAL REFERENCE (V)
1.0
1.0
1.0
V
V
REF
REF
1.5
1.5
(V)
(V)
1.5
2.0
2.0
REF
REF
INL (POSITIVE)
INL (NEGATIVE)
DNL (POSITIVE)
DNL (NEGATIVE)
REF
, f
SCL
Data Sheet
2.0
= 400 kHz
2.5
2.5
2.5
3.0
3.0