HSC-INTERFACEBOARD AD [Analog Devices], HSC-INTERFACEBOARD Datasheet - Page 12

• Manufacturer Part Number: HSC-INTERFACEBOARD
• Description: 1.75 MSPS, 4 mW 10-Bit/12-Bit Parallel ADCs
• Manufacturer: AD [Analog Devices]

AD7470/AD7472
Mode 1
Figure 14 shows the AD7472 conversion sequence in Mode 1
using a throughput rate of 500 kSPS and a clock frequency of
26 MHz. At 5 V supply the current consumption for the part
when converting is 2 mA and the quiescent current is 650 µA.
The conversion time of 531.66 ns contributes 2.658 mW to the
overall power dissipation in the following way:
The contribution to the total power dissipated by the remaining
1.468 µs of the cycle is 2.38 mW.
Thus the power dissipated during each cycle is:
Mode 2
Figure 15 shows the AD7472 conversion sequence in Mode 2
using a throughput rate of 500 kSPS and a clock frequency of
26 MHz. At 5 V supply the current consumption for the part
when converting is 2 mA, while the sleep current is 1 µA max.
The power dissipated during this power-down is negligible and
is thus not worth considering in the total power figure. During
the wake-up phase, the AD7472 will draw 650 µA. Overall
power dissipated is:
(
531 66
CONVST
.
BUSY
CONVST
BUSY
ns
/
(531.66 ns/2 µs) × (5 × 2 mA) = 2.658 mW
2
(1.468 µs/2 µs) × (5 × 650 µA) = 2.38 mW
Figure 14. Mode 1 Power Dissipation
Figure 15. Mode 2 Power Dissipation
µ
s
2.658 mW + 2.38 mW = 5.038 mW
)
t
WAKEUP
×
1 s
(
5
×
t
531.66ns
CONVERT
2
mA
t
531.66ns
CONVERT
)
+
(
2 s
1
µ
s
2 s
/
2
µ
s
t
)
QUIESCENT
1.468 s
×
t
(
QUIESCENT
5
1.468 s
×
650
µ
A
)
=
4 283
.
mW
–12–
Figure 16 and Figure 17 show a typical graphical representation
of Power vs. Throughput for the AD7472 when in (a) Mode 1
@ 5 V and 3 V and Mode 2 @ 5 V and 3 V.
Figure 16. Power vs. Throughput (Mode 1 @ 5 V and 3 V)
Figure 17. Power vs. Throughput (Mode 2 @ 5 V and 3 V)
–0.2
–0.4
–0.6
–0.8
0.8
0.6
0.4
0.2
–1
7
6
5
4
3
2
1
0
8
7
6
5
4
3
2
1
0
Figure 18. Typical INL for 2.75 V @ +25 ° C
1
0
50
0
50 100
512
300
150
200
1024
600
250
THROUGHPUT – kHz
300
THROUGHPUT – kHz
1536
+5V
800
350
CODE
2048
400 450 500 550
1000
+3V
+5V
+3V
2560
1100
3072
600
1300
650
3584
700
1500
750
4096
REV. A