5

dc2326af

DEMO MANUAL DC2326A

Dc2326a setup

Layout

As with any high performance ADC, this part is sensitive

to layout. The area immediately surrounding the ADC on

the DC2326A should be used as a guideline for placement,

and routing of the various components associated with

the ADC. Here are some things to remember when laying

out a board for the LTC2345. A ground plane is necessary

to obtain maximum performance. Keep bypass capacitors

as close to supply pins as possible. Use individual low

impedance returns for all bypass capacitors. Use of a

symmetrical layout around the analog inputs will minimize

theeffectsofparasiticelements.Shieldanaloginputtraces

with ground to minimize coupling from other traces. Keep

traces as short as possible.

Component Selection

When driving a low noise, low distortion ADC such as the

LTC2345, component selection is important so as to not

degrade performance. Resistors should have low values

to minimize noise and distortion. Metal film resistors are

recommended to reduce distortion caused by self heat-

ing. Because of their low voltage coefficients, to further

reduce distortion NPO or silver mica capacitors should be

used. Any buffer used to drive the LTC2345 should have

low distortion, low noise and a fast settling time such as

the LT1355.