AD7656 Analog Devices, AD7656 Datasheet - Page 15

• Manufacturer Part Number: AD7656
• Description: 250 kSPS, 6-Channel, Simultaneous Sampling Bipolar 16-Bit ADC
• Manufacturer: Analog Devices

Specifications of AD7656

• Resolution (bits): 16bit
• # Chan: 6
• Sample Rate: 250kSPS
• Interface: Par,Ser,SPI
• Analog Input Type: SE-Bip
• Ain Range: Bip (Vref) x 2,Bip (Vref) x 4,Bip 10V,Bip 5.0V
• Adc Architecture: SAR
• Pkg Type: QFP

–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
90
85
80
75
70
65
60
0
0
10
0
0
f
INTERNAL REFERENCE
T
SAMPLE
A
Figure 12. AD7656 SINAD vs. Input Frequency
= 25°C
500
500
= 250kSPS
Figure 11. AD7658 Typical DNL
Figure 10. AD7658 Typical INL
1000
1000
ANALOG INPUT FREQUENCY (kHz)
AV
V
V
±10V RANGE
DRIVE
DD
CC
/V
/DV
1500
1500
SS
= +4.75 V
CC
= ±10V
/
AV
V
V
±5V RANGE
2000
CODE
2000
CODE
DRIVE
DD
100
CC
/V
/DV
SS
AV
V
±10V RANGE
= +5V
AV
V
f
2 × V
AV
V
f
2 × V
DD
SAMPLE
2500
SAMPLE
2500
CC
= ±5.25V
DD
DD
CC
/V
CC
CC
/
/V
/V
/DV
SS
REF
REF
/DV
/DV
SS
SS
CC
= ±16.5V
= 250kSPS
3000
= 250kSPS
3000
CC
= ±12V
= ±12V
RANGE
CC
RANGE
/V
AV
V
V
±5V RANGE
/V
/V
DRIVE
DRIVE
DD
DRIVE
DRIVE
CC
/V
3500
3500
/DV
SS
= +5.25V
= +5V
= +5V
= +5V
= ±12V
CC
/
4095
4095
1000
Rev. C | Page 15 of 32
Figure 14. AD7656 THD vs. Input Frequency for Various Source Impedances,
Figure 15. AD7656 THD vs. Input Frequency for Various Source Impedances,
–100
–110
–120
–100
–110
–120
–100
–110
–120
–40
–50
–60
–70
–80
–90
–60
–70
–80
–90
–60
–70
–80
–90
10
10
10
V
AV
T
INTERNAL REFERENCE
±4 × V
V
AV
T
INTERNAL REFERENCE
±2 × V
f
INTERNAL REFERENCE
T
SAMPLE
A
A
DD
A
DD
Figure 13. AD7656 THD vs. Input Frequency
CC
CC
= 25°C
= 25°C
= 25°C
R
/V
/V
AV
V
V
±10V RANGE
SOURCE
DRIVE
DD
/DV
/DV
SS
SS
REF
REF
CC
/V
R
= 250kSPS
= ±16.5V
= ±12V
CC
CC
/DV
SOURCE
SS
RANGE
RANGE
= +4.75V
/V
/V
ANALOG INPUT FREQUENCY (kHz)
ANALOG INPUT FREQUENCY (kHz)
ANALOG INPUT FREQUENCY (kHz)
= ±10V
CC
= 220Ω
DRIVE
DRIVE
/
AD7656/AD7657/AD7658
R
R
±4 × V
= 10Ω
±2 × V
SOURCE
SOURCE
= +5.25V
= +5V
R
SOURCE
AV
V
±5V RANGE
REF
REF
DD
= 50Ω
= 100Ω
CC
Range
Range
/V
100
/DV
SS
R
= 100Ω
SOURCE
= ±5.25V
AV
V
V
±10V RANGE
CC
R
DRIVE
DD
R
R
SOURCE
R
/V
SOURCE
CC
SOURCE
SOURCE
/V
DRIVE
/DV
SS
= +5.25V
= 50Ω
= ±16.5V
CC
= 1000Ω
= +5V
= 10Ω
= 1000Ω
/
AV
V
V
±5V RANGE
= 220Ω
DRIVE
DD
CC
/V
/DV
SS
= +5V
CC
= ±12V
/
1000
100
100