AD7691 Analog Devices, AD7691 Datasheet - Page 6

• Manufacturer Part Number: AD7691
• Manufacturer: Analog Devices

Specifications of AD7691

• Resolution (bits): 18bit
• # Chan: 1
• Sample Rate: 250kSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p
• Adc Architecture: SAR
• Pkg Type: CSP,SOP

AD7691
VDD = 2.3 V to 4.5 V, VIO = 2.3 V to VDD, V
Table 5.
Parameter
Conversion Time: CNV Rising Edge to Data Available
Acquisition Time
Time Between Conversions
CNV Pulse Width (CS Mode)
SCK Period (CS Mode)
SCK Period (Chain Mode)
SCK Low Time
SCK High Time
SCK Falling Edge to Data Remains Valid
SCK Falling Edge to Data Valid Delay
CNV or SDI Low to SDO D17 MSB Valid (CS Mode)
CNV or SDI High or Last SCK Falling Edge to SDO High Impedance (CS Mode)
SDI Valid Setup Time from CNV Rising Edge (CS Mode)
SDI Valid Hold Time from CNV Rising Edge (CS Mode)
SCK Valid Setup Time from CNV Rising Edge (Chain Mode)
SCK Valid Hold Time from CNV Rising Edge (Chain Mode)
SDI Valid Setup Time from SCK Falling Edge (Chain Mode)
SDI Valid Hold Time from SCK Falling Edge (Chain Mode)
SDI High to SDO High (Chain Mode with Busy Indicator)
1
See Figure 3 and Figure 4 for load conditions.
VIO Above 3 V
VIO Above 2.7 V
VIO Above 2.3 V
VIO Above 3 V
VIO Above 2.7 V
VIO Above 2.3 V
VIO Above 2.7 V
VIO Above 2.3 V
Figure 3. Load Circuit for Digital Interface Timing
TO SDO
50pF
C
L
500µA
500µA
I
I
OL
OH
1.4V
REF
= VDD, all specifications T
Rev. B | Page 6 of 28
MIN
Symbol
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
CONV
ACQ
CYC
CNVH
SCK
SCK
SCKL
SCKH
HSDO
DSDO
EN
DIS
SSDICNV
HSDICNV
SSCKCNV
HSCKCNV
SSDISCK
HSDISCK
DSDOSDI
30% VIO
1
2
2V IF VIO ABOVE 2.5V, VIO – 0.5V IF VIO BELOW 2.5V.
0.8V IF VIO ABOVE 2.5V, 0.5V IF VIO BELOW 2.5V.
to T
t
DELAY
MAX
, unless otherwise noted.
Figure 4. Voltage Levels for Timing
29
35
40
Min
0.5
1.8
5.5
10
25
12
12
5
30
0
5
8
8
10
2V OR VIO – 0.5V
0.8V OR 0.5V
2
Typ
1
70% VIO
1
t
Max
3.7
24
30
35
18
22
25
36
DELAY
2V OR VIO – 0.5V
0.8V OR 0.5V
2
ns
ns
ns
ns
ns
ns
Unit
μs
ns
μs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
1