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8

Document Number: 70047

S-71241–Rev. F, 25-Jun-07

Vishay Siliconix

DG308B/309B

APPLICATIONS

Figure 6. A Precision Amplifier with Digitally Programmable Inputs and Gains

Gain =

Gain 1 (x 1)

Gain 2 (x 10)

Gain 3 (x 100)

Gain 4 (x 1000)

- 15 V

+ 15 V

- 15 V

GND

DG419

30 pF

+ 15 V

+ 15 V

- 15 V

DG308B

Logic High = Switch On

+

-

LM101A

CH

18 k

Ω

9.9 k

Ω

100 k

Ω

100

Ω

100

Ω

2 k

Ω

V+

V-

GND

V-

+ 5 V

Figure 7. Sample-and-Hold

LM101A

+ 15 V

- 15 V

30 pF

15 V

- 15 V

V+

V-

DG309B

50 pF

1000 pF

J202

J500

J507

+ 15 V

2N4400

- 15 V

1 k

Ω

200

Ω

5 M

Ω

5.1 M

Ω

Aquisition Time

= 25 µs

Aperature Time

= 1 µs

Sample to Hold Offset

= 5 mV

Droop Rate

= 5 mV/s

Logic Input

Low = Sample

High = Hold

-

+