ADS5553

SLWS158 − FEBRUARY 2005

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18

requiring dc coupling of the input. Flexible in their

configurations (see Figure 31), such amplifiers can be

used for single-ended-to-differential conversion, signal

amplification.

Table 1. Recommended Amplifiers to Drive the Input of the ADS5553

INPUT SIGNAL FREQUENCY

RECOMMENDED AMPLIFIER

TYPE OF AMPLIFIER

USE WITH TRANSFORMER?

DC to 20 MHz

THS4503/6

Differential In/Out Amp

No

DC to 50 MHz

OPA847

Operational Amp

Yes

OPA695

Operational Amp

Yes

10 MHz to 120 MHz

THS3201

Operational Amp

Yes

THS3202

Operational Amp

Yes

Over 100 MHz

THS9001

RF Gain Block

Yes

100 Ω

+

−

OPA695

AINM

AINP

5 V

CM

400 Ω

0.1 mF

ADS5553

0.1 µF

1:1

−5 V

57.5 Ω

(18 dB)

100 Ω

1000 pF

10 Ω

Figure 30. Converting a Single-Ended Input Signal to a Differential Signal Using an RF Transformer

INM

3.3 V

5 V

10 µF

0.1 µF

THS4503

ADS5553

14-Bit/65 MSPS

1 µF

10 µF

0.1 µF

−5 V

10 Ω

0.1 µF

INP

CM

Figure 31. Using the THS4503 With the ADS5553