AD604

REV. 0

–17–

20

27

28

15

16

17

18

19

24

25

26

22

14

13

10

3

4

9

6

5

AD9050

COMP

AINB

ENCODE

OR

AIN

(MSB) D9

D8

D5

D6

D7

D4

D3

D2

D1

(LSB) D0

+5V

+5V

A/D

OUTPUT

13

16

15

14

24

23

22

21

20

19

18

17

12

11

10

9

8

1

2

3

4

7

6

5

AD604

0.1µF

0.1µF

0.1µF

1k

Ω

0.1µF

50

Ω

CLK

0.1µF

50

Ω

J2

ANALOG

INPUT

100

Ω

12

11

20

19

18

17

16

15

14

13

10

9

8

1

2

3

4

7

6

5

AD7226

AGND

DGND

DB7

(MSB)

DB6

DB5

DB4

A1

A0

WR

DB0

(LSB)

DB1

DB2

DB3

VREF

+15V

DIGITAL GAIN CONTROL

0.1µF

FILTER

1k

Ω

2

3

6

AD9631

1k

Ω

OPTIONAL

0.1µF

0.1µF

0.1µF

0.1µF

–IN

+IN

OUT

–DSX1

+DSX1

PAI1

FBK1

PAO1

COM1

COM2

PAI2

FBK2

PAO2

+DSX2

–DSX2

VGN1

VREF

VPOS

GND1

OUT1

VNEG

VNEG

VPOS

GND2

OUT2

VOCM

VGN2

Figure 50. TGC Circuit for Medical Ultrasound Application

AD604

DUT

0.1µF

450

Ω

PAI

49.9

Ω

OUT

R

A

HP3577B

50

Ω

HP11636B

POWER

SPLITTER

Figure 52. Setup for Gain Measurements

13

16

15

14

19

18

17

24

23

22

21

20

12

11

10

9

8

1

2

3

4

7

6

5

AD604

R1

500

Ω

+5V

–5V

C6

0.1µF

C11

0.1µF

C4

0.1µF

IN1

VREF

OUT1

VOCM

C2

5pF

C12

0.1µF

R4

500

Ω

C10

0.1µF

C5

0.1µF

C8

5pF

C9

0.1µF

C7

0.1µF

VG1

VG2

OUT2

R3

RGN

C1

0.1µF

R2

RGN

NOTE 2

NOTE 3

NOTE 3

IN2

PAO2

PAO1

C3

0.1µF

NOTES:

1. PAO1 AND PAO2 ARE USED TO MEASURE PREAMPS.

2. RGN = 0 NOMINALLY; PREAMP GAIN = 5, RGN = OPEN; PREAMP GAIN = 10

3. WHEN MEASURING BW WITH 50

Ω SPECTRUM ANALYZER, USE 450Ω IN SERIES.

–DSX1

+DSX1

PAI1

FBK1

PAO1

COM1

COM2

PAI2

FBK2

PAO2

+DSX2

–DSX2

VGN1

VREF

VPOS

GND1

OUT1

VNEG

VNEG

VPOS

GND2

OUT2

VOCM

VGN2

OPTIONAL

Figure 51. Basic Test Board