9

SHC5320

®

FIGURE 10. PAM Output.

Hold

Sample

Mode

Control

Analog Input

PAM Output

DATA DISTRIBUTION

The SHC5320 may be used to hold the output of a digital-

to-analog converter and distribute several different analog

voltages to different loads (see Figure 11).

HIGH-SPEED DATA ACQUISITION

The minimum sample time for one channel in a data acqui-

sition system is usually considered to be the acquisition time

of the sample/hold plus the conversion time of the A/D

converter. If two or more sample/holds are used with a

multiplexer (such as the Burr-Brown MPC800 or MPC801)

as shown in Figure 12, the acquisition time of the sample/

hold can be virtually eliminated. While the first channel is in

hold and switched into the A/ D converter, the multiplexer

may be addressed to the next channel. The second sample/

hold will have acquired this signal by the time the conver-

sion is complete. Then, the sample/holds reverse roles and

another channel is addressed. In low level systems an instru-

mentation amplifier (such as the Burr-Brown INA101) and

a differential multiplexer (such as the Burr-Brown MPC509A

or MPC507A) may be required in front of the sample/hold.

The settling and acquisition times of the multiplexer, instru-

mentation amplifier, and sample/hold can be eliminated

from the total conversion time as before by operating in this

overlapped mode with the sample/holds.

Additional SHC5320 Units

D/A

Converter

Parallel

Inputs

Digital

Inputs

Mode

Control

Logic

SHC5320

1

2

14

6

Analog

Outputs

Channel 1

SHC5320

1

2

14

6

Channel 2

SHC5320

1

2

14

6

Channel N

Signal

Common

7

7

7

FIGURE 11. Typical Data Distribution Configuration.