Datasheet

REV. D
AD8001
–13–
0.1F
+V
S
–V
S
20
50
1k
18
17
16
15
14
13
12
11
–V
REF A
10pF
CLOCK
5, 9, 22,
24, 37, 41
4,19, 21 25, 27, 42
0.1F
38
8
–V
REF B
6
+V
INT
2
3
+V
REF A
A
IN A
649
324ANALOG
IN A
0.5V
1.3k
AD707
43
+V
REF B
20k
0.1F
–2V
1.3k
20k
649
ANALOG
IN B
0.5V
324
20
0.1F
40
COMP
1
A
IN B
ENCODE A ENCODE B
10
36
ENCODE
74ACT04
0.1F
+5V
28
29
30
31
32
33
34
35
RZ1
RZ2
D
0A
(LSB)
D
7A
(MSB)
D
0B
(LSB)
D
7B
(MSB)
7, 20,
26, 39
–5V
1N4001
AD9058
(J-LEAD)
RZ1, RZ2 = 2,000 SIP (8-PKG)
74ACT 273
74ACT 273
8
8
AD8001
AD8001
Figure 12. AD8001 Driving a Dual A-to-D Converter
Driving A-to-D Converters
The AD8001 is well suited for driving high speed analog-to-
digital converters such as the AD9058. The AD9058 is a dual
8-bit 50 MSPS ADC. In the circuit below, the AD8001 is
shown driving the inputs of the AD9058, which are configured
for 0 V to 2 V ranges. Bipolar input signals are buffered, amplified
(–2×), and offset (by +1.0 V) into the proper input range of the
ADC. Using the AD9058’s internal +2 V reference connected
to both ADCs as shown in Figure 12 reduces the number of
external components required to create a complete data
acquisition system. The 20 Ω resistors in series with ADC inputs
are used to help the AD8001s drive the 10 pF ADC input
capacitance. The AD8001 only adds 100 mW to the power
consumption while not limiting the performance of the circuit.