AD8002ARM View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

AD8002ARM

Dual 600 MHz, 50 mW Current Feedback Amplifier

Analog Devices 

AD8002

Driving A-to-D Converters

The AD8002 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 Figure 10, the AD8002 is shown driv-

ing 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 10 reduces the number of external compo-

nents required to create a complete data acquisition system. The

20 Ω resistors in series with ADC inputs are used to help the

AD8002s drive the 10 pF ADC input capacitance. The AD8002

adds only 100 mW to the power consumption, while not limit-

ing the performance of the circuit.

ANALOG

IN A

؎0.5V

274⍀

1.1k⍀

–2V

0.1␮F

1.1k⍀

ANALOG

IN B

؎0.5V

274⍀

549⍀

1/2

50⍀ AD8002

AD707

20k⍀

549⍀

1/2

50⍀ AD8002

RZ1, RZ2 = 2,000⍀ SIP (8-PKG)

ENCODE

74ACT04

1k⍀

10

36

50⍀

ENCODE A

8

–VREF A

38

–VREF B

ENCODE B

+VS

5, 9, 22,

24, 37, 41

+5V

0.1␮F

20⍀

20k⍀

0.1␮F

20⍀

0.1␮F

6 AIN A

2

+VINT

3

+VREF A

43

+VREF B

18

D0A (LSB) 17

16

15

14

13

12

D7A (MSB) 11

AD9058

(J-LEAD)

40

AIN B

1

COMP

28

D0B (LSB) 29

30

31

32

33

34

D7B (MSB)

–VS

35

7, 20,

26, 39

4,19, 21 25, 27, 42

0.1␮F

RZ1

RZ2

–5V

1N4001

10pF

8

8

CLOCK

Figure 10. AD8002 Driving a Dual A-to-D Converter

–12–

REV. D

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