ADS5500

SBAS303C − DECEMBER 2003 − REVISED MARCH 2004

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23

Table 4. Recommended Amplifiers to Drive the Input of the ADS5500

INPUT SIGNAL FREQUENCY

RECOMMENDED AMPLIFIER

TYPE OF AMPLIFIER

USE WITH TRANSFORMER?

DC to 20MHz

THS4503

Differential In/Out Amp

No

DC to 50MHz

OPA847

Operational Amp

Yes

OPA695

Operational Amp

Yes

10MHz to 120MHz

THS3201

Operational Amp

Yes

10MHz to 120MHz

THS3202

Operational Amp

Yes

Over 100MHz

THS9001

RF Gain Block

Yes

R

IN

R

IN

C

IN

0.1

µF

R

T

100

Ω

0.1

µF

1000pF

1:1

R

S

100

Ω

OPA695

R

1

400

Ω

A

(18dB)

R

2

57.5

Ω

V

IN

ADS5500

INP

INM

CM

−5V

+5V

10

Ω

Figure 6. Converting a Single-Ended Input Signal to a Differential Signal Using an RF Transformer

R

F

R

G

V

OCM

INP

INM

CM

R

F

R

G

R

S

ADS5500

14−Bit/125MSPS

0.1

µF

0.1

µF

10

µF

1

µF

R

T

+3.3V

+5V

0.1

µF

10

µF

−5V

THS4503

R

IN

R

IN

10

Ω

Figure 7. Using the THS4503 with the ADS5500