AD7626 Analog Devices, AD7626 Datasheet - Page 21

• Manufacturer Part Number: AD7626
• Description: 16-Bit, 10 MSPS, PulSAR Differential ADC
• Manufacturer: Analog Devices

Specifications of AD7626

• Resolution (bits): 16bit
• # Chan: 1
• Sample Rate: 10MSPS
• Interface: LVDS,Ser
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p
• Adc Architecture: SAR
• Pkg Type: CSP

Wake-Up Time from EN1= 0, EN0 = 0
The AD7626 powers down when EN1 and EN0 are both set to
0. Selecting the correct reference choice from power-down, the
user sets EN1 and EN0 to the required value shown in Table 8.
The user may immediately apply CNV pulses to receive data
conversion results. Typical wake-up times for the selected
reference settings are shown in Table 9. Each time represents
the duration from the EN1, EN0 logic transition to when the
output of the ADC is settled to 0.5 LSB accuracy.
Table 9. Wake-Up Time from EN1=0, EN0 = 0
A
B
C
POWER SUPPLY
The AD7626 uses both 5 V (VDD1) and 2.5 V (VDD2) power
supplies, as well as a digital input/output interface supply (VIO).
VIO allows a direct interface with 2.5 V logic only. VIO and
VDD2 can be taken from the same 2.5 V source; however, it is
best practice to isolate the VIO and VDD2 pins using separate
traces as well as to decouple each pin separately.
The 5 V and 2.5 V supplies required for the AD7626 can be
generated using Analog Devices, Inc., LDOs such as
the ADP3330-2.5, ADP3330-5, ADP3334, and ADP1708.
Reference Mode
Power-up
Internal reference and inter-
nal reference buffer in use
External 1.2 V reference
applied to REFIN pin
External 4.096 V reference
applied to REF pin
90
85
80
75
70
65
60
55
50
1
(350 mV pp Ripple on VDD2, 600 mV Ripple on VDD1)
VDD2
VDD1
Figure 38. PSRR vs. Supply Frequency
10
SUPPLY FREQUENCY (Hz)
100
INTERNAL REFERENCE USED
EN1
1
0
1
EN0
1
1
0
1k
9.5 sec
Wake-Up
Time (0.5 LSB
Accuracy)
25 ms
65 μs
10k
Rev. A | Page 21 of 2
Power-Up
When powering up the AD7626 device, first apply the 2.5 V
VDD2 supply and VIO voltage to the device. After the VIO and
2.5 V VDD2 have been established, apply the 5 V VDD1 supply.
If using an external reference with the AD7626, ensure that the
EN0 and EN1 pins are connected to the correct logic values
associated with the reference option of choice and then apply
the external reference voltage. Finally, apply the analog inputs to
the ADC.
160
140
120
100
25
20
15
10
80
60
40
20
5
0
0
0
0
Figure 39. Current Consumption vs. Sampling Rate
Figure 40. Power Dissipation vs. Sampling Rate
1
VIO INTERNAL
REFERENCE
2
INTERNAL REFERENCE
2
VDD1 INTERNAL
REFERENCE
3
THROUGHPUT (MSPS)
THROUGHPUT (MSPS)
VDD2 INTERNAL
REFERENCE
4
4
VDD1 EXTERNAL
REFERENCE
5
VDD2 EXTERNAL
REFERENCE
6
EXTERNAL REFERENCE
6
VIO EXTERNAL
REFERENCE
7
8
8
AD7626
9
1
0
1
0